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NSInvocationSEL 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 0x100000000double 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yesBOOL 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=Aboutprefs:root=General&path=ACCESSIBILITYprefs:root=AIRPLANE_MODEprefs:root=General&path=AUTOLOCKprefs:root=General&path=USAGE/CELLULAR_USAGEprefs:root=Brightnessprefs:root=Bluetoothprefs:root=General&path=DATE_AND_TIMEprefs:root=FACETIMEprefs:root=Generalprefs:root=General&path=Keyboardprefs:root=CASTLEprefs:root=CASTLE&path=STORAGE_AND_BACKUPprefs:root=General&path=INTERNATIONALprefs:root=LOCATION_SERVICESprefs:root=ACCOUNT_SETTINGSprefs:root=MUSICprefs:root=MUSIC&path=EQprefs:root=MUSIC&path=VolumeLimitprefs:root=General&path=Networkprefs:root=NIKE_PLUS_IPODprefs:root=NOTESprefs:root=NOTIFICATIONS_IDprefs:root=Phoneprefs:root=Photosprefs:root=General&path=ManagedConfigurationListprefs:root=General&path=Resetprefs:root=Sounds&path=Ringtoneprefs:root=Safariprefs:root=General&path=Assistantprefs:root=Soundsprefs:root=General&path=SOFTWARE_UPDATE_LINKprefs:root=STOREprefs:root=TWITTERprefs:root=FACEBOOKprefs:root=General&path=USAGE prefs:root=VIDEOprefs:root=General&path=Network/VPNprefs:root=Wallpaperprefs:root=WIFIprefs:root=INTERNET_TETHERINGprefs:root=Phone&path=Blockedprefs: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>"; 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]];
}