转载：多年iOS开发经验总结(二)

转载地址：http://www.jianshu.com/p/9fcd37c0ea05

1、设置UILabel行间距

NSMutableAttributedString* attrString = [[NSMutableAttributedString  alloc] initWithString:label.text];
    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
    [style setLineSpacing:20];
    [attrString addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(0, label.text.length)];
    label.attributedText = attrString;

// 或者使用xib，看下gif图

Untitled.gif

2、当使用-performSelector:withObject:withObject:afterDelay:方法时，需要传入多参数问题

// 方法一、
// 把参数放进一个数组／字典，直接把数组／字典当成一个参数传过去，具体方法实现的地方再解析这个数组／字典
NSArray * array = 
    [NSArray arrayWithObjects: @"first", @"second", nil];
[self performSelector:@selector(fooFirstInput:) withObject: array afterDelay:15.0];

// 方法二、
// 使用NSInvocation
SEL aSelector = NSSelectorFromString(@"doSoming:argument2:");
    NSInteger argument1 = 10;
    NSString *argument2 = @"argument2";
    if([self respondsToSelector:aSelector]) {
        NSInvocation *inv = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:aSelector]];
        [inv setSelector:aSelector];
        [inv setTarget:self];
        [inv setArgument:&(argument1) atIndex:2];
        [inv setArgument:&(argument2) atIndex:3];
        [inv performSelector:@selector(invoke) withObject:nil afterDelay:15.0];
    }

3、UILabel显示不同颜色字体

NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:label.text];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,5)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(5,6)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(11,5)];
label.attributedText = string;

4、比较两个CGRect/CGSize/CGPoint是否相等

if (CGRectEqualToRect(rect1, rect2)) { // 两个区域相等
        // do some
    }
    if (CGPointEqualToPoint(point1, point2)) { // 两个点相等
        // do some
    }
    if (CGSizeEqualToSize(size1, size2)) { // 两个size相等
        // do some
    }

5、比较两个NSDate相差多少小时

 NSDate* date1 = someDate;
 NSDate* date2 = someOtherDate;
 NSTimeInterval distanceBetweenDates = [date1 timeIntervalSinceDate:date2];
 double secondsInAnHour = 3600;
// 除以3600是把秒化成小时，除以60得到结果为相差的分钟数
 NSInteger hoursBetweenDates = distanceBetweenDates / secondsInAnHour;

6、每个cell之间增加间距

// 方法一，每个分区只显示一行cell，分区头当作你想要的间距(注意，从数据源数组中取值的时候需要用indexPath.section而不是indexPath.row)
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return yourArry.count;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 1;
}
-(CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
    return cellSpacingHeight;
}

// 方法二，在cell的contentView上加个稍微低一点的view，cell上原本的内容放在你的view上，而不是contentView上，这样能伪造出一个间距来。

// 方法三，自定义cell，重写setFrame：方法
- (void)setFrame:(CGRect)frame
{
    frame.size.height -= 20;
    [super setFrame:frame];
}

7、播放一张张连续的图片

// 加入现在有三张图片分别为animate_1、animate_2、animate_3
// 方法一
    imageView.animationImages = @[[UIImage imageNamed:@"animate_1"], [UIImage imageNamed:@"animate_2"], [UIImage imageNamed:@"animate_3"]];
imageView.animationDuration = 1.0;
// 方法二
    imageView.image = [UIImage animatedImageNamed:@"animate_" duration:1.0];
// 方法二解释下，这个方法会加载animate_为前缀的，后边0-1024，也就是animate_0、animate_1一直到animate_1024

8、加载gif图片

推荐使用这个框架 FLAnimatedImage

9、防止离屏渲染为image添加圆角

// image分类
- (UIImage *)circleImage
{
// NO代表透明
UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);
// 获得上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
// 添加一个圆
CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
// 方形变圆形
CGContextAddEllipseInRect(ctx, rect);
// 裁剪
CGContextClip(ctx);
// 将图片画上去
[self drawInRect:rect];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}

10、查看系统所有字体

// 打印字体
for (id familyName in [UIFont familyNames]) {
    NSLog(@"%@", familyName);
    for (id fontName in [UIFont fontNamesForFamilyName:familyName]) NSLog(@"  %@", fontName);
}
// 也可以进入这个网址查看 http://iosfonts.com/

11、获取随机数

NSInteger i = arc4random();

12、获取随机数小数(0-1之间)

#define ARC4RANDOM_MAX      0x100000000
double val = ((double)arc4random() / ARC4RANDOM_MAX);

13、AVPlayer视频播放完成的通知监听

[[NSNotificationCenter defaultCenter] 
      addObserver:self
      selector:@selector(videoPlayEnd)
      name:AVPlayerItemDidPlayToEndTimeNotification 
      object:nil];

14、判断两个rect是否有交叉

 if (CGRectIntersectsRect(rect1, rect2)) {
}

15、判断一个字符串是否为数字

NSCharacterSet *notDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
    if ([str rangeOfCharacterFromSet:notDigits].location == NSNotFound)
    {
      // 是数字
    } else
    {
      // 不是数字
    }

16、将一个view保存为pdf格式

- (void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename
{
    NSMutableData *pdfData = [NSMutableData data];
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();
    [aView.layer renderInContext:pdfContext];
    UIGraphicsEndPDFContext();

    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);
    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@"documentDirectoryFileName: %@",documentDirectoryFilename);
}

17、让一个view在父视图中心

child.center = [parent convertPoint:parent.center fromView:parent.superview];

18、获取当前导航控制器下前一个控制器

- (UIViewController *)backViewController
{
    NSInteger myIndex = [self.navigationController.viewControllers indexOfObject:self];

    if ( myIndex != 0 && myIndex != NSNotFound ) {
        return [self.navigationController.viewControllers objectAtIndex:myIndex-1];
    } else {
        return nil;
    }
}

19、保存UIImage到本地

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Image.png"];

[UIImagePNGRepresentation(image) writeToFile:filePath atomically:YES];

20、键盘上方增加工具栏

UIToolbar *keyboardDoneButtonView = [[UIToolbar alloc] init];
[keyboardDoneButtonView sizeToFit];
UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done"
                                                               style:UIBarButtonItemStyleBordered target:self
                                                              action:@selector(doneClicked:)];
[keyboardDoneButtonView setItems:[NSArray arrayWithObjects:doneButton, nil]];
txtField.inputAccessoryView = keyboardDoneButtonView;

21、copy一个view

因为UIView没有实现copy协议，因此找不到copyWithZone方法，使用copy的时候导致崩溃
但是我们可以通过归档再解档实现copy，这相当于对视图进行了一次深拷贝，代码如下

id copyOfView = 
[NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:originalView]];

22、在image上绘制文字并生成新的image

UIFont *font = [UIFont boldSystemFontOfSize:12];
    UIGraphicsBeginImageContext(image.size);
    [image drawInRect:CGRectMake(0,0,image.size.width,image.size.height)];
    CGRect rect = CGRectMake(point.x, point.y, image.size.width, image.size.height);
    [[UIColor whiteColor] set];
    [text drawInRect:CGRectIntegral(rect) withFont:font]; 
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

23、判断一个view是否为另一个view的子视图

// 如果myView是self.view本身，也会返回yes
BOOL isSubView = [myView isDescendantOfView:self.view];

24、判断一个字符串是否包含另一个字符串

// 方法一、这种方法只适用于iOS8之后，如果是配iOS8之前用方法二
if ([str containsString:otherStr]) NSLog(@"包含");

// 方法二
NSRange range = [str rangeOfString:otherStr];
if (range.location != NSNotFound) NSLog(@"包含");

25、UICollectionView自动滚动到某行

// 重写viewDidLayoutSubviews方法
-(void)viewDidLayoutSubviews {
   [super viewDidLayoutSubviews];
   [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredVertically animated:NO];
}

26、修改系统UIAlertController

// 但是据说这种方法会被App Store拒绝(慎用！)
UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];
    NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"我是一个大文本"];
    [hogan addAttribute:NSFontAttributeName
                  value:[UIFont systemFontOfSize:30]
                  range:NSMakeRange(4, 1)];
    [hogan addAttribute:NSForegroundColorAttributeName
                  value:[UIColor redColor]
                  range:NSMakeRange(4, 1)];
    [alertVC setValue:hogan forKey:@"attributedTitle"];

    UIAlertAction *button = [UIAlertAction actionWithTitle:@"Label text" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){ }];
    UIImage *accessoryImage = [UIImage imageNamed:@"1"];
    [button setValue:accessoryImage forKey:@"image"];
    [alertVC addAction:button];
    [self presentViewController:alertVC animated:YES completion:nil];

27、判断某一行的cell是否已经显示

CGRect cellRect = [tableView rectForRowAtIndexPath:indexPath];
BOOL completelyVisible = CGRectContainsRect(tableView.bounds, cellRect);

28、让导航控制器pop回指定的控制器

NSMutableArray *allViewControllers = [NSMutableArray arrayWithArray:[self.navigationController viewControllers]];
for (UIViewController *aViewController in allViewControllers) {
    if ([aViewController isKindOfClass:[RequiredViewController class]]) {
        [self.navigationController popToViewController:aViewController animated:NO];
    }
}

29、动画修改label上的文字

// 方法一
CATransition *animation = [CATransition animation];
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.type = kCATransitionFade;
    animation.duration = 0.75;
    [self.label.layer addAnimation:animation forKey:@"kCATransitionFade"];
    self.label.text = @"New";

// 方法二
[UIView transitionWithView:self.label
                      duration:0.25f
                       options:UIViewAnimationOptionTransitionCrossDissolve
                    animations:^{

                        self.label.text = @"Well done!";

                    } completion:nil];

// 方法三
[UIView animateWithDuration:1.0
                     animations:^{
                         self.label.alpha = 0.0f;
                         self.label.text = @"newText";
                         self.label.alpha = 1.0f;
                     }];

30、判断字典中是否包含某个key值

if ([dic objectForKey:@"yourKey"]) {
    NSLog(@"有这个值");
} else {
    NSLog(@"没有这个值");
}

31、获取屏幕方向

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;

if(orientation == 0) //Default orientation 
    //默认
else if(orientation == UIInterfaceOrientationPortrait)
    //竖屏
else if(orientation == UIInterfaceOrientationLandscapeLeft)
    // 左横屏
else if(orientation == UIInterfaceOrientationLandscapeRight)
    //右横屏

32、设置UIImage的透明度

// 方法一、添加UIImage分类
- (UIImage *)imageByApplyingAlpha:(CGFloat) alpha {
    UIGraphicsBeginImageContextWithOptions(self.size, NO, 0.0f);

    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGRect area = CGRectMake(0, 0, self.size.width, self.size.height);

    CGContextScaleCTM(ctx, 1, -1);
    CGContextTranslateCTM(ctx, 0, -area.size.height);

    CGContextSetBlendMode(ctx, kCGBlendModeMultiply);

    CGContextSetAlpha(ctx, alpha);

    CGContextDrawImage(ctx, area, self.CGImage);

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;
}

// 方法二、如果没有奇葩需求，干脆用UIImageView设置透明度
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageWithName:@"yourImage"]];
imageView.alpha = 0.5;

33、Attempt to mutate immutable object with insertString:atIndex:

这个错是因为你拿字符串调用insertString:atIndex:方法的时候，调用对象不是NSMutableString，应该先转成这个类型再调用

34、UIWebView添加单击手势不响应

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(webViewClick)];
        tap.delegate = self;
        [_webView addGestureRecognizer:tap];

// 因为webView本身有一个单击手势，所以再添加会造成手势冲突，从而不响应。需要绑定手势代理，并实现下边的代理方法
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    return YES;
}

35、获取手机RAM容量

// 需要导入#import <mach/mach.h>
mach_port_t host_port;
    mach_msg_type_number_t host_size;
    vm_size_t pagesize;

    host_port = mach_host_self();
    host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
    host_page_size(host_port, &pagesize);

    vm_statistics_data_t vm_stat;

    if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) {
        NSLog(@"Failed to fetch vm statistics");
    }

    /* Stats in bytes */
    natural_t mem_used = (vm_stat.active_count +
                          vm_stat.inactive_count +
                          vm_stat.wire_count) * pagesize;
    natural_t mem_free = vm_stat.free_count * pagesize;
    natural_t mem_total = mem_used + mem_free;
    NSLog(@"已用: %u 可用: %u 总共: %u", mem_used, mem_free, mem_total);

36、地图上两个点之间的实际距离

// 需要导入#import <CoreLocation/CoreLocation.h>
CLLocation *locA = [[CLLocation alloc] initWithLatitude:34 longitude:113];
    CLLocation *locB = [[CLLocation alloc] initWithLatitude:31.05 longitude:121.76];
// CLLocationDistance求出的单位为米
    CLLocationDistance distance = [locA distanceFromLocation:locB];

37、在应用中打开设置的某个界面

// 打开设置->通用
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=General"]];

// 以下是设置其他界面
prefs:root=General&path=About
prefs:root=General&path=ACCESSIBILITY
prefs:root=AIRPLANE_MODE
prefs:root=General&path=AUTOLOCK
prefs:root=General&path=USAGE/CELLULAR_USAGE
prefs:root=Brightness
prefs:root=Bluetooth
prefs:root=General&path=DATE_AND_TIME
prefs:root=FACETIME
prefs:root=General
prefs:root=General&path=Keyboard
prefs:root=CASTLE
prefs:root=CASTLE&path=STORAGE_AND_BACKUP
prefs:root=General&path=INTERNATIONAL
prefs:root=LOCATION_SERVICES
prefs:root=ACCOUNT_SETTINGS
prefs:root=MUSIC
prefs:root=MUSIC&path=EQ
prefs:root=MUSIC&path=VolumeLimit
prefs:root=General&path=Network
prefs:root=NIKE_PLUS_IPOD
prefs:root=NOTES
prefs:root=NOTIFICATIONS_ID
prefs:root=Phone
prefs:root=Photos
prefs:root=General&path=ManagedConfigurationList
prefs:root=General&path=Reset
prefs:root=Sounds&path=Ringtone
prefs:root=Safari
prefs:root=General&path=Assistant
prefs:root=Sounds
prefs:root=General&path=SOFTWARE_UPDATE_LINK
prefs:root=STORE
prefs:root=TWITTER
prefs:root=FACEBOOK
prefs:root=General&path=USAGE prefs:root=VIDEO
prefs:root=General&path=Network/VPN
prefs:root=Wallpaper
prefs:root=WIFI
prefs:root=INTERNET_TETHERING
prefs:root=Phone&path=Blocked
prefs:root=DO_NOT_DISTURB

38、在UITextView中显示html文本

    UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(20, 30, 100, 199)];
    textView.backgroundColor = [UIColor redColor];
    [self.view addSubview:textView];
    NSString *htmlString = @"<h1>Header</h1><h2>Subheader</h2><p>Some <em>text</em></p>![](http://blogs.babble.com/famecrawler/files/2010/11/mickey_mouse-1097.jpg)";
    NSAttributedString *attributedString = [[NSAttributedString alloc] initWithData: [htmlString dataUsingEncoding:NSUnicodeStringEncoding] options: @{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType } documentAttributes: nil error: nil];
    textView.attributedText = attributedString;

39、监听scrollView是否滚动到了顶部／底部

-(void)scrollViewDidScroll: (UIScrollView*)scrollView
{
    float scrollViewHeight = scrollView.frame.size.height;
    float scrollContentSizeHeight = scrollView.contentSize.height;
    float scrollOffset = scrollView.contentOffset.y;

    if (scrollOffset == 0)
    {
        // 滚动到了顶部
    }
    else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight)
    {
        // 滚动到了底部
    }
}

40、UISlider增量／减量为固定值(假如为5)

- (void)setupSlider
{
    UISlider *slider = [[UISlider alloc] init];
    [self.view addSubview:slider];
    [slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged];
    slider.maximumValue = 100;
    slider.minimumValue = 0;
    slider.frame = CGRectMake(200, 20, 100, 30);
}

- (void)sliderAction:(UISlider *)slider
{
    [slider setValue:((int)((slider.value + 2.5) / 5) * 5) animated:NO];
}

41、选中textField或者textView所有文本(我这里以textView为例)

[self.textView setSelectedTextRange:[self.textView textRangeFromPosition:self.textView.beginningOfDocument toPosition:self.textView.endOfDocument]]

42、从导航控制器中删除某个控制器

// 方法一、知道这个控制器所处的导航控制器下标
NSMutableArray *navigationArray = [[NSMutableArray alloc] initWithArray: self.navigationController.viewControllers];
[navigationArray removeObjectAtIndex: 2]; 
self.navigationController.viewControllers = navigationArray;

// 方法二、知道具体是哪个控制器
NSArray* tempVCA = [self.navigationController viewControllers];

for(UIViewController *tempVC in tempVCA)
{
    if([tempVC isKindOfClass:[urViewControllerClass class]])
    {
        [tempVC removeFromParentViewController];
    }
}

43、隐藏UITextView/UITextField光标

textField.tintColor = [UIColor clearColor];

44、当UITextView/UITextField中没有文字时，禁用回车键

textField.enablesReturnKeyAutomatically = YES;

45、字符串encode编码(编码url字符串不成功的问题)

// 我们一般用这个方法处理stringByAddingPercentEscapesUsingEncoding但是这个方法好想不会处理／和&这种特殊符号，这种情况就需要用下边这个方法处理
@implementation NSString (NSString_Extended)
- (NSString *)urlencode {
    NSMutableString *output = [NSMutableString string];
    const unsigned char *source = (const unsigned char *)[self UTF8String];
    int sourceLen = strlen((const char *)source);
    for (int i = 0; i < sourceLen; ++i) {
        const unsigned char thisChar = source[i];
        if (thisChar == ' '){
            [output appendString:@"+"];
        } else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' || 
                   (thisChar >= 'a' && thisChar <= 'z') ||
                   (thisChar >= 'A' && thisChar <= 'Z') ||
                   (thisChar >= '0' && thisChar <= '9')) {
            [output appendFormat:@"%c", thisChar];
        } else {
            [output appendFormat:@"%%%02X", thisChar];
        }
    }
    return output;
}

46、计算UILabel上某段文字的frame

@implementation UILabel (TextRect)

- (CGRect)boundingRectForCharacterRange:(NSRange)range
{
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:[self attributedText]];
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    [textStorage addLayoutManager:layoutManager];
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:[self bounds].size];
    textContainer.lineFragmentPadding = 0;
    [layoutManager addTextContainer:textContainer];
    NSRange glyphRange;
    [layoutManager characterRangeForGlyphRange:range actualGlyphRange:&glyphRange];
    return [layoutManager boundingRectForGlyphRange:glyphRange inTextContainer:textContainer];
}

47、获取随机UUID

NSString *result;
    if([[[UIDevice currentDevice] systemVersion] floatValue] > 6.0)
    {
       result = [[NSUUID UUID] UUIDString];
    }
    else
    {
        CFUUIDRef uuidRef = CFUUIDCreate(NULL);
        CFStringRef uuid = CFUUIDCreateString(NULL, uuidRef);
        CFRelease(uuidRef);
        result = (__bridge_transfer NSString *)uuid;
    }

48、仿苹果抖动动画

#define RADIANS(degrees) (((degrees) * M_PI) / 180.0)

- (void)startAnimate {
    view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(-5));

    [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse) animations:^ {
                         view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(5));
                     } completion:nil];
}

- (void)stopAnimate {
    [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveLinear) animations:^ {
                         view.transform = CGAffineTransformIdentity;
                     } completion:nil];
}

49、修改UISearBar内部背景颜色

UITextField *textField = [_searchBar valueForKey:@"_searchField"];
textField.backgroundColor = [UIColor redColor];

50、UITextView滚动到顶部

    // 方法一
    [self.textView scrollRangeToVisible:NSMakeRange(0, 0)];
    // 方法二
    [self.textView setContentOffset:CGPointZero animated:YES];

51、通知监听APP生命周期

UIApplicationDidEnterBackgroundNotification 应用程序进入后台
UIApplicationWillEnterForegroundNotification 应用程序将要进入前台
UIApplicationDidFinishLaunchingNotification 应用程序完成启动
UIApplicationDidFinishLaunchingNotification 应用程序由挂起变的活跃
UIApplicationWillResignActiveNotification 应用程序挂起(有电话进来或者锁屏)
UIApplicationDidReceiveMemoryWarningNotification 应用程序收到内存警告
UIApplicationDidReceiveMemoryWarningNotification 应用程序终止(后台杀死、手机关机等)
UIApplicationSignificantTimeChangeNotification 当有重大时间改变(凌晨0点，设备时间被修改，时区改变等)
UIApplicationWillChangeStatusBarOrientationNotification 设备方向将要改变
UIApplicationDidChangeStatusBarOrientationNotification 设备方向改变
UIApplicationWillChangeStatusBarFrameNotification 设备状态栏frame将要改变
UIApplicationDidChangeStatusBarFrameNotification 设备状态栏frame改变
UIApplicationBackgroundRefreshStatusDidChangeNotification 应用程序在后台下载内容的状态发生变化
UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件被锁定,无法访问
UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件可用了

52、触摸事件类型

UIControlEventTouchCancel 取消控件当前触发的事件
UIControlEventTouchDown 点按下去的事件
UIControlEventTouchDownRepeat 重复的触动事件
UIControlEventTouchDragEnter 手指被拖动到控件的边界的事件
UIControlEventTouchDragExit 一个手指从控件内拖到外界的事件
UIControlEventTouchDragInside 手指在控件的边界内拖动的事件
UIControlEventTouchDragOutside 手指在控件边界之外被拖动的事件
UIControlEventTouchUpInside 手指处于控制范围内的触摸事件
UIControlEventTouchUpOutside 手指超出控制范围的控制中的触摸事件

53、UITextField文字周围增加边距

    // 子类化UITextField，增加insert属性
@interface WZBTextField : UITextField
@property (nonatomic, assign) UIEdgeInsets insets;
@end

// 在.m文件重写下列方法
- (CGRect)textRectForBounds:(CGRect)bounds {
    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);
    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) {
        return [self adjustRectWithWidthRightView:paddedRect];
    }
    return paddedRect;
}

- (CGRect)placeholderRectForBounds:(CGRect)bounds {
    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);

    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) {
        return [self adjustRectWithWidthRightView:paddedRect];
    }
    return paddedRect;
}

- (CGRect)editingRectForBounds:(CGRect)bounds {
    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);
    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeWhileEditing) {
        return [self adjustRectWithWidthRightView:paddedRect];
    }
    return paddedRect;
}

- (CGRect)adjustRectWithWidthRightView:(CGRect)bounds {
    CGRect paddedRect = bounds;
    paddedRect.size.width -= CGRectGetWidth(self.rightView.frame);

    return paddedRect;
}

54、监听UISlider拖动状态

// 添加事件
[slider addTarget:self action:@selector(sliderValurChanged:forEvent:) forControlEvents:UIControlEventValueChanged];

// 实现方法
- (void)sliderValurChanged:(UISlider*)slider forEvent:(UIEvent*)event {
    UITouch *touchEvent = [[event allTouches] anyObject];
    switch (touchEvent.phase) {
        case UITouchPhaseBegan:
            NSLog(@"开始拖动");
            break;
        case UITouchPhaseMoved:
            NSLog(@"正在拖动");
            break;
        case UITouchPhaseEnded:
            NSLog(@"结束拖动");
            break;
        default:
            break;
    }
}

55、设置UITextField光标位置

// textField需要设置的textField，index要设置的光标位置
- (void)cursorLocation:(UITextField *)textField index:(NSInteger)index
{
    NSRange range = NSMakeRange(index, 0);
    UITextPosition *start = [textField positionFromPosition:[textField beginningOfDocument] offset:range.location];
    UITextPosition *end = [textField positionFromPosition:start offset:range.length];
    [textField setSelectedTextRange:[textField textRangeFromPosition:start toPosition:end]];
}

56、去除webView底部黑色

    [webView setBackgroundColor:[UIColor clearColor]];
    [webView setOpaque:NO];

    for (UIView *v1 in [webView subviews])
    {
        if ([v1 isKindOfClass:[UIScrollView class]])
        {
            for (UIView *v2 in v1.subviews)
            {
                if ([v2 isKindOfClass:[UIImageView class]])
                {
                    v2.hidden = YES;
                }
            }
        }
    }

57、获取collectionViewCell在屏幕中的frame

UICollectionViewLayoutAttributes *attributes = [collectionView layoutAttributesForItemAtIndexPath:indexPath];
CGRect cellRect = attributes.frame;
CGRect cellFrameInSuperview = [collectionView convertRect:cellRect toView:[cv superview]];

58、比较两个UIImage是否相等

- (BOOL)image:(UIImage *)image1 isEqualTo:(UIImage *)image2
{
    NSData *data1 = UIImagePNGRepresentation(image1);
    NSData *data2 = UIImagePNGRepresentation(image2);

    return [data1 isEqual:data2];
}

59、解决当UIScrollView上有UIButton的时候，触摸到button滑动不了的问题

// 子类化UIScrollView，并重写以下方法
- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.delaysContentTouches = NO;
    }

    return self;
}

- (BOOL)touchesShouldCancelInContentView:(UIView *)view {
    if ([view isKindOfClass:UIButton.class]) {
        return YES;
    }

    return [super touchesShouldCancelInContentView:view];
}

60、UITextView中的文字添加阴影效果

- (void)setTextLayer:(UITextView *)textView color:(UIColor *)color
{
    CALayer *textLayer = ((CALayer *)[textView.layer.sublayers objectAtIndex:0]);
    textLayer.shadowColor = color.CGColor;
    textLayer.shadowOffset = CGSizeMake(0.0f, 1.0f);
    textLayer.shadowOpacity = 1.0f;
    textLayer.shadowRadius = 1.0f;
}

61、MD5加密

+ (NSString *)md5:(NSString *)str
{
    const char *concat_str = [str UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(concat_str, (unsigned int)strlen(concat_str), result);
    NSMutableString *hash = [NSMutableString string];
    for (int i =0; i <16; i++){
        [hash appendFormat:@"%02X", result[i]];
    }
    return [hash uppercaseString];
}

62、base64加密

@interface NSData (Base64)
/**
 *  @brief  字符串base64后转data
 */
+ (NSData *)dataWithBase64EncodedString:(NSString *)string
{
    if (![string length]) return nil;
    NSData *decoded = nil;
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    if (![NSData instancesRespondToSelector:@selector(initWithBase64EncodedString:options:)])
    {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        decoded = [[self alloc] initWithBase64Encoding:[string stringByReplacingOccurrencesOfString:@"[^A-Za-z0-9+/=]" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, [string length])]];
#pragma clang diagnostic pop
    }
    else
#endif
    {
        decoded = [[self alloc] initWithBase64EncodedString:string options:NSDataBase64DecodingIgnoreUnknownCharacters];
    }
    return [decoded length]? decoded: nil;
}
/**
 *  @brief  NSData转string
 *  @param wrapWidth 换行长度  76  64
 */
- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth
{
    if (![self length]) return nil;
    NSString *encoded = nil;
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    if (![NSData instancesRespondToSelector:@selector(base64EncodedStringWithOptions:)])
    {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        encoded = [self base64Encoding];
#pragma clang diagnostic pop

    }
    else
#endif
    {
        switch (wrapWidth)
        {
            case 64:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
            }
            case 76:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength];
            }
            default:
            {
                encoded = [self base64EncodedStringWithOptions:(NSDataBase64EncodingOptions)0];
            }
        }
    }
    if (!wrapWidth || wrapWidth >= [encoded length])
    {
        return encoded;
    }
    wrapWidth = (wrapWidth / 4) * 4;
    NSMutableString *result = [NSMutableString string];
    for (NSUInteger i = 0; i < [encoded length]; i+= wrapWidth)
    {
        if (i + wrapWidth >= [encoded length])
        {
            [result appendString:[encoded substringFromIndex:i]];
            break;
        }
        [result appendString:[encoded substringWithRange:NSMakeRange(i, wrapWidth)]];
        [result appendString:@"
"];
    }
    return result;
}
/**
 *  @brief  NSData转string 换行长度默认64
 */
- (NSString *)base64EncodedString
{
    return [self base64EncodedStringWithWrapWidth:0];
}

63、AES加密

#import <CommonCrypto/CommonCryptor.h>
@interface NSData (AES)
/**
 *  利用AES加密数据
 */
- (NSData*)encryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];

    CCCryptorStatus status = CCCrypt(kCCEncrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes, encryptedData.length,&dataMoved);

    if (status == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }

    return nil;

}

/**
 *  @brief  利用AES解密据
 */
- (NSData*)decryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];

    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes, decryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }

    return nil;

}

64、3DES加密

#import <CommonCrypto/CommonCryptor.h>
@interface NSData (3DES)
/**
 *  利用3DES加密数据
 */
- (NSData*)encryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];

    CCCryptorStatus result = CCCrypt(kCCEncrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes,encryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }

    return nil;

}
/**
 *  @brief   利用3DES解密数据
 */
- (NSData*)decryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];

    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes,decryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }

    return nil;

}

65、单个页面多个网络请求的情况，需要监听所有网络请求结束后刷新UI

dispatch_group_t group = dispatch_group_create();
    dispatch_queue_t serialQueue = dispatch_queue_create("com.wzb.test.www", DISPATCH_QUEUE_SERIAL);
    dispatch_group_enter(group);
    dispatch_group_async(group, serialQueue, ^{
        // 网络请求一
        [WebClick getDataSuccess:^(ResponseModel *model) {
            dispatch_group_leave(group);
        } failure:^(NSString *err) {
            dispatch_group_leave(group);
        }];
    });
    dispatch_group_enter(group);
    dispatch_group_async(group, serialQueue, ^{
        // 网络请求二
        [WebClick getDataSuccess:getBigTypeRM onSuccess:^(ResponseModel *model) {
            dispatch_group_leave(group);
        }                                  failure:^(NSString *errorString) {
            dispatch_group_leave(group);
        }];
    });
    dispatch_group_enter(group);
    dispatch_group_async(group, serialQueue, ^{
        // 网络请求三
        [WebClick getDataSuccess:^{
            dispatch_group_leave(group);
        } failure:^(NSString *errorString) {
            dispatch_group_leave(group);
        }];
    });

    // 所有网络请求结束后会来到这个方法
    dispatch_group_notify(group, serialQueue, ^{
        dispatch_async(dispatch_get_global_queue(0, 0), ^{
            dispatch_async(dispatch_get_main_queue(), ^{
                // 刷新UI
            });
        });
    });

66、解决openUrl延时问题

// 方法一
dispatch_async(dispatch_get_main_queue(), ^{

    UIApplication *application = [UIApplication sharedApplication];
    if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
        [application openURL:URL options:@{}
           completionHandler:nil];
    } else {
        [application openURL:URL];
    }
    });
// 方法二
[self performSelector:@selector(redirectToURL:) withObject:url afterDelay:0.1];

- (void) redirectToURL
{
UIApplication *application = [UIApplication sharedApplication];
    if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
        [application openURL:URL options:@{}
           completionHandler:nil];
    } else {
        [application openURL:URL];
    }
}

67、页面跳转实现翻转动画

// modal方式
    TestViewController *vc = [[TestViewController alloc] init];
    vc.view.backgroundColor = [UIColor redColor];
    vc.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
    [self presentViewController:vc animated:YES completion:nil];

// push方式
    TestViewController *vc = [[TestViewController alloc] init];
    vc.view.backgroundColor = [UIColor redColor];
    [UIView beginAnimations:@"View Flip" context:nil];
    [UIView setAnimationDuration:0.80];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.navigationController.view cache:NO];
    [self.navigationController pushViewController:vc animated:YES];
    [UIView commitAnimations];

68、tableView实现无限滚动

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat actualPosition = scrollView.contentOffset.y;
    CGFloat contentHeight = scrollView.contentSize.height - scrollView.frame.size.height;
    if (actualPosition >= contentHeight) {
        [self.dataArr addObjectsFromArray:self.dataArr];
        [self.tableView reloadData];
    }
}

69、代码方式调整屏幕亮度

// brightness属性值在0-1之间，0代表最小亮度，1代表最大亮度
[[UIScreen mainScreen] setBrightness:0.5];

70、获取当前应用CUP用量

float cpu_usage()
{
    kern_return_t kr;
    task_info_data_t tinfo;
    mach_msg_type_number_t task_info_count;

    task_info_count = TASK_INFO_MAX;
    kr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)tinfo, &task_info_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }

    task_basic_info_t      basic_info;
    thread_array_t         thread_list;
    mach_msg_type_number_t thread_count;

    thread_info_data_t     thinfo;
    mach_msg_type_number_t thread_info_count;

    thread_basic_info_t basic_info_th;
    uint32_t stat_thread = 0; // Mach threads

    basic_info = (task_basic_info_t)tinfo;

    // get threads in the task
    kr = task_threads(mach_task_self(), &thread_list, &thread_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }
    if (thread_count > 0)
        stat_thread += thread_count;

    long tot_sec = 0;
    long tot_usec = 0;
    float tot_cpu = 0;
    int j;

    for (j = 0; j < (int)thread_count; j++)
    {
        thread_info_count = THREAD_INFO_MAX;
        kr = thread_info(thread_list[j], THREAD_BASIC_INFO,
                         (thread_info_t)thinfo, &thread_info_count);
        if (kr != KERN_SUCCESS) {
            return -1;
        }

        basic_info_th = (thread_basic_info_t)thinfo;

        if (!(basic_info_th->flags & TH_FLAGS_IDLE)) {
            tot_sec = tot_sec + basic_info_th->user_time.seconds + basic_info_th->system_time.seconds;
            tot_usec = tot_usec + basic_info_th->user_time.microseconds + basic_info_th->system_time.microseconds;
            tot_cpu = tot_cpu + basic_info_th->cpu_usage / (float)TH_USAGE_SCALE * 100.0;
        }

    } // for each thread

    kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));
    assert(kr == KERN_SUCCESS);

    return tot_cpu;
}

71、float数据取整四舍五入

    CGFloat f = 4.65;
    NSLog(@"%d", (int)f);    // 打印结果4

    CGFloat f = 4.65;
    NSLog(@"%d", (int)round(f));    // 打印结果5

72、删除UISearchBar系统默认边框

    // 方法一
    searchBar.searchBarStyle = UISearchBarStyleMinimal;

    // 方法二
    [searchBar setBackgroundImage:[[UIImage alloc]init]];

    // 方法三
    searchBar.barTintColor = [UIColor whiteColor];

73、为UICollectionViewCell设置圆角和阴影

cell.contentView.layer.cornerRadius = 2.0f;
cell.contentView.layer.borderWidth = 1.0f;
cell.contentView.layer.borderColor = [UIColor clearColor].CGColor;
cell.contentView.layer.masksToBounds = YES;

cell.layer.shadowColor = [UIColor lightGrayColor].CGColor;
cell.layer.shadowOffset = CGSizeMake(0, 2.0f);
cell.layer.shadowRadius = 2.0f;
cell.layer.shadowOpacity = 1.0f;
cell.layer.masksToBounds = NO;
cell.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect:cell.bounds cornerRadius:cell.contentView.layer.cornerRadius].CGPath;

74、让正在滑动的scrollView停止滚动(不是禁止，而是暂时停止滚动)

[scrollView setContentOffset:scrollView.contentOffset animated:NO];

75、使用xib设置UIView的边框、圆角

圆角和边框看下图即可设置

xib设置圆角边框.png

但是增加layer.borderColor的keyPath设置边框颜色并不能起作用，后来查了资料，这里应该用layer.borderUIColor，但是这里设置的颜色不起作用，无论设置什么颜色显示出来的都是黑色的。后来又去查了下，有种解决方案是给CALayer添加一个分类，提供一个 - (void)setBorderUIColor:(UIColor *)color;方法就可以解决了，实现如下：

xib设置边框颜色.png

#import "CALayer+BorderColor.h"

@implementation CALayer (BorderColor)

- (void)setBorderUIColor:(UIColor *)color
{
    self.borderColor = color.CGColor;
}

76、根据经纬度获取城市等信息

// 创建经纬度
    CLLocation *location = [[CLLocation alloc] initWithLatitude:latitude longitude:longitude];
    //创建一个译码器
    CLGeocoder *cLGeocoder = [[CLGeocoder alloc] init];
    [cLGeocoder reverseGeocodeLocation:userLocation completionHandler:^(NSArray *placemarks, NSError *error) {
        CLPlacemark *place = [placemarks objectAtIndex:0];
        // 位置名
    　　NSLog(@"name,%@",place.name);
    　　// 街道
    　　NSLog(@"thoroughfare,%@",place.thoroughfare);
    　　// 子街道
    　　NSLog(@"subThoroughfare,%@",place.subThoroughfare);
    　　// 市
    　　NSLog(@"locality,%@",place.locality);
    　　// 区
    　　NSLog(@"subLocality,%@",place.subLocality); 
    　　// 国家
    　　NSLog(@"country,%@",place.country);
        }
    }];

/*  CLPlacemark中属性含义
name                    地名

thoroughfare            街道

subThoroughfare        街道相关信息，例如门牌等

locality                城市

subLocality            城市相关信息，例如标志性建筑

administrativeArea      直辖市

subAdministrativeArea  其他行政区域信息（自治区等）

postalCode              邮编

ISOcountryCode          国家编码

country                国家

inlandWater            水源，湖泊

ocean                  海洋

areasOfInterest        关联的或利益相关的地标
*/

77、如何防止添加多个NSNotification观察者？

// 解决方案就是添加观察者之前先移除下这个观察者
[[NSNotificationCenter defaultCenter] removeObserver:observer name:name object:object];
        [[NSNotificationCenter defaultCenter] addObserver:observer selector:selector name:name object:object];

78、将一个xib添加到另外一个xib上

// 假设你的自定义view名字为CustomView，你需要在CustomView.m中重写 `- (instancetype)initWithCoder:(NSCoder *)aDecoder` 方法，代码如下：
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if ((self = [super initWithCoder:aDecoder])) {
        [self addSubview:[[[NSBundle mainBundle] loadNibNamed:@"CustomView" owner:self options:nil] objectAtIndex:0]];
    }
    return self;
}

将一个xib添加到另外一个xib上.png

79、处理字符串，使其首字母大写

    NSString *str = @"abcdefghijklmn";
    NSString *resultStr;
    if (str && str.length > 0) {
        resultStr = [str stringByReplacingCharactersInRange:NSMakeRange(0,1) withString:[[str substringToIndex:1] capitalizedString]];
    }
    NSLog(@"%@", resultStr);

80、判断一个UIAlertView/UIAlertController是否显示

// UIAlertView自带属性
if (alert.visible)
{
      NSLog(@"显示了");
} else {
      NSLog(@"未显示");
}

// UIAlertController没有visible属性，需要自己判断，添加一个全局变量 BOOL visible
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
    UIAlertAction *alertAction = [UIAlertAction actionWithTitle:@"ActionTitle" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        self.visible = NO;
    }];
    UIAlertAction *calcelAction = [UIAlertAction actionWithTitle:@"calcelTitle" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
        self.visible = NO;
    }];
    [alertController addAction:alertAction];
    [alertController addAction:calcelAction];
    [self presentViewController:alertController animated:YES completion:^{
        self.visible = YES;
    }];

81、获取字符串中的数字

- (NSString *)getNumberFromStr:(NSString *)str
{
    NSCharacterSet *nonDigitCharacterSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
    return [[str componentsSeparatedByCharactersInSet:nonDigitCharacterSet] componentsJoinedByString:@""];
}

    NSLog(@"%@", [self getNumberFromStr:@"a0b0c1d2e3f4fda8fa8fad9fsad23"]); // 00123488923

82、为UIView的某个方向添加边框

// 添加UIView分类

// UIView+WZB.h
#import <UIKit/UIKit.h>


/**
 边框方向

 - WZBBorderDirectionTop: 顶部
 - WZBBorderDirectionLeft: 左边
 - WZBBorderDirectionBottom: 底部
 - WZBBorderDirectionRight: 右边
 */
typedef NS_ENUM(NSInteger, WZBBorderDirectionType) {
    WZBBorderDirectionTop = 0,
    WZBBorderDirectionLeft,
    WZBBorderDirectionBottom,
    WZBBorderDirectionRight
};

@interface UIView (WZB)


/**
 为UIView的某个方向添加边框

 @param direction 边框方向
 @param color 边框颜色
 @param width 边框宽度
 */
- (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color (CGFloat)width;

@end

// UIView+WZB.m
#import "UIView+WZB.h"

@implementation UIView (WZB)

- (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color (CGFloat)width
{
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;
    switch (direction) {
        case WZBBorderDirectionTop:
        {
            border.frame = CGRectMake(0.0f, 0.0f, self.bounds.size.width, width);
        }
            break;
        case WZBBorderDirectionLeft:
        {
            border.frame = CGRectMake(0.0f, 0.0f, width, self.bounds.size.height);
        }
            break;
        case WZBBorderDirectionBottom:
        {
            border.frame = CGRectMake(0.0f, self.bounds.size.height - width, self.bounds.size.width, width);
        }
            break;
        case WZBBorderDirectionRight:
        {
            border.frame = CGRectMake(self.bounds.size.width - width, 0, width, self.bounds.size.height);
        }
            break;

        default:
            break;
    }
    [self.layer addSublayer:border];
}

83、通过属性设置UISwitch、UIProgressView等控件的宽高

mySwitch.transform = CGAffineTransformMakeScale(5.0f, 5.0f);

progressView.transform = CGAffineTransformMakeScale(5.0f, 5.0f);

84、自动搜索功能，用户连续输入的时候不搜索，用户停止输入的时候自动搜索(我这里设置的是0.5s，可根据需求更改)

// 输入框文字改变的时候调用
-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{
    // 先取消调用搜索方法
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(searchNewResult) object:nil];
    // 0.5秒后调用搜索方法
    [self performSelector:@selector(searchNewResult) withObject:nil afterDelay:0.5];
}

85、修改UISearchBar的占位文字颜色

    // 方法一（推荐使用）
    UITextField *searchField = [searchBar valueForKey:@"_searchField"];
    [searchField setValue:[UIColor blueColor] forKeyPath:@"_placeholderLabel.textColor"];

    // 方法二（已过期）
    [[UILabel appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:[UIColor redColor]];

    // 方法三（已过期）
    NSDictionary *placeholderAttributes = @{NSForegroundColorAttributeName : [UIColor redColor], NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue" size:15],};
    NSAttributedString *attributedPlaceholder = [[NSAttributedString alloc] initWithString:searchBar.placeholder attributes:placeholderAttributes];
    [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setAttributedPlaceholder:attributedPlaceholder];

86、某个界面多个事件同时响应引起的问题(比如，两个button同时按push到新界面，两个都会响应，可能导致push重叠)

// UIView有个属性叫做exclusiveTouch，设置为YES后，其响应事件会和其他view互斥(有其他view事件响应的时候点击它不起作用)
view.exclusiveTouch = YES;

// 一个一个设置太麻烦了，可以全局设置
[[UIView appearance] setExclusiveTouch:YES];

// 或者只设置button
[[UIButton appearance] setExclusiveTouch:YES];

87、修改tabBar的frame

// 子类化UITabBarViewController，我这里以修改tabBar高度为例，重写viewWillLayoutSubviews方法
#import "WZBTabBarViewController.h"

@interface WZBTabBarViewController ()

@end

@implementation WZBTabBarViewController
- (void)viewWillLayoutSubviews {

    CGRect tabFrame = self.tabBar.frame;
    tabFrame.size.height = 100;
    tabFrame.origin.y = self.view.frame.size.height - 100;
    self.tabBar.frame = tabFrame;
}
@end

88、修改键盘背景颜色

// 设置某个键盘颜色
    textField.keyboardAppearance = UIKeyboardAppearanceAlert;

// 设置工程中所有键盘颜色
[[UITextField appearance] setKeyboardAppearance:UIKeyboardAppearanceAlert];

89、修改image颜色

UIImage *image = [UIImage imageNamed:@"test"];
    imageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
    CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextClipToMask(context, rect, image.CGImage);
    CGContextSetFillColorWithColor(context, [[UIColor redColor] CGColor]);
    CGContextFillRect(context, rect);
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    UIImage *flippedImage = [UIImage imageWithCGImage:img.CGImage scale:1.0 orientation: UIImageOrientationDownMirrored];
    imageView.image = flippedImage;

90、动画执行removeFromSuperview

    [UIView animateWithDuration:0.2
                     animations:^{
                         view.alpha = 0.0f;
                     } completion:^(BOOL finished){
                         [view removeFromSuperview];
                     }];

91、设置UIButton高亮背景颜色

    [UIView animateWithDuration:0.2
                     animations:^{
                         view.alpha = 0.0f;
                     } completion:^(BOOL finished){
                         [view removeFromSuperview];
                     }];

92、设置UIButton高亮时的背景颜色

// 方法一、子类化UIButton，重写setHighlighted:方法，代码如下
#import "WZBButton.h"

@implementation WZBButton

- (void)setHighlighted:(BOOL)highlighted {
    [super setHighlighted:highlighted];

    UIColor *normalColor = [UIColor greenColor];
    UIColor *highlightedColor = [UIColor redColor];
    self.backgroundColor = highlighted ? highlightedColor : normalColor;

}

// 方法二、利用setBackgroundImage:forState:方法
[button setBackgroundImage:[self imageWithColor:[UIColor blueColor]] forState:UIControlStateHighlighted];

- (UIImage *)imageWithColor:(UIColor *)color {
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}

93、关于图片拉伸

推荐看这个博客，讲的很详细http://blog.csdn.net/q199109106q/article/details/8615661

94、利用runtime获取一个类所有属性

- (NSArray *)allPropertyNames:(Class)aClass
{
    unsigned count;
    objc_property_t *properties = class_copyPropertyList(aClass, &count);

    NSMutableArray *rv = [NSMutableArray array];

    unsigned i;
    for (i = 0; i < count; i++)
    {
        objc_property_t property = properties[i];
        NSString *name = [NSString stringWithUTF8String:property_getName(property)];
        [rv addObject:name];
    }

    free(properties);

    return rv;
}

95、设置textView的某段文字变成其他颜色

- (void)setupTextView:(UITextView *)textView text:(NSString *)text color:(UIColor *)color {
    NSMutableAttributedString *string = [[NSMutableAttributedString alloc]initWithString:textView.text];
    [string addAttribute:NSForegroundColorAttributeName value:color range:[textView.text rangeOfString:text]];
    [textView setAttributedText:string];
}

96、让push跳转动画像modal跳转动画那样效果(从下往上推上来)

- (void)push
{
TestViewController *vc = [[TestViewController alloc] init];
    vc.view.backgroundColor = [UIColor redColor];
    CATransition* transition = [CATransition animation];
    transition.duration = 0.4f;
    transition.type = kCATransitionMoveIn;
    transition.subtype = kCATransitionFromTop;
    [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];
    [self.navigationController pushViewController:vc animated:NO];
}

- (void)pop
{
CATransition* transition = [CATransition animation];
    transition.duration = 0.4f;
    transition.type = kCATransitionReveal;
    transition.subtype = kCATransitionFromBottom;
    [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];
    [self.navigationController popViewControllerAnimated:NO];
}

97、上传图片太大，压缩图片

-(UIImage *)resizeImage:(UIImage *)image
{
    float actualHeight = image.size.height;
    float actualWidth = image.size.width;
    float maxHeight = 300.0;
    float maxWidth = 400.0;
    float imgRatio = actualWidth/actualHeight;
    float maxRatio = maxWidth/maxHeight;
    float compressionQuality = 0.5;//50 percent compression

    if (actualHeight > maxHeight || actualWidth > maxWidth)
    {
        if(imgRatio < maxRatio)
        {
            //adjust width according to maxHeight
            imgRatio = maxHeight / actualHeight;
            actualWidth = imgRatio * actualWidth;
            actualHeight = maxHeight;
        }
        else if(imgRatio > maxRatio)
        {
            //adjust height according to maxWidth
            imgRatio = maxWidth / actualWidth;
            actualHeight = imgRatio * actualHeight;
            actualWidth = maxWidth;
        }
        else
        {
            actualHeight = maxHeight;
            actualWidth = maxWidth;
        }
    }

    CGRect rect = CGRectMake(0.0, 0.0, actualWidth, actualHeight);
    UIGraphicsBeginImageContext(rect.size);
    [image drawInRect:rect];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    NSData *imageData = UIImageJPEGRepresentation(img, compressionQuality);
    UIGraphicsEndImageContext();

    return [UIImage imageWithData:imageData];

}