iOS开发技巧

1.TableView隐藏没有内容的cell

self.tableView.tableFooterView = [[UIView alloc] init];

2.自定义了leftBarbuttonItem左滑返回手势失效

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]
                                         initWithImage:img
                                         style:UIBarButtonItemStylePlain
                                         target:self
                                         action:@selector(onBack:)];
self.navigationController.interactivePopGestureRecognizer.delegate = (id<UIGestureRecognizerDelegate>)self;

3.ScrollView莫名其妙不能在viewController划到顶

self.automaticallyAdjustsScrollViewInsets = NO;

4.app老是不流畅

这个神器叫做:KMCGeigerCounter

5.在不新建一个Cell的情况下调整separaLine的位置

_myTableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);

6.点击self.view就让键盘收起

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
   [self.view endEditing:YES];
}

7.在代码里改在xib里添加的layoutAttribute

像拉button一样的拉你的约束.nslayoutattribute也是可以拉线的.

8.像safari一样滑动的时候隐藏navigationbar

navigationController.hidesBarsOnSwipe = Yes

9.导航条返回键带的title消失

[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)
                                                     forBarMetrics:UIBarMetricsDefault];

10.CollectionView 实现tableview那种悬停的header

CSStickyHeaderFlowLayout

11.拉伸图片的时候让图片不变形

UIImage *image = [[UIImage imageNamed:@"xxx"] stretchableImageWithLeftCapWidth:10 topCapHeight:10];
(现在的方法叫resizableImageWithCapInsets).

12.播放GIF的时候卡

FlipBoard出品的太适合你了。https://github.com/Flipboard/FLAnimatedImage

13.把tableview里cell的小对勾的颜色改成别的颜色

_mTableView.tintColor = [UIColor redColor];

14.本来我的statusbar是lightcontent的，结果用UIImagePickerController会导致我的statusbar的样式变成黑色

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
}

15.把navigationbar弄成透明的而不是带模糊的效果

[self.navigationBar setBackgroundImage:[UIImage new]
                         forBarMetrics:UIBarMetricsDefault];
self.navigationBar.shadowImage = [UIImage new];
self.navigationBar.translucent = YES;

16改变uitextfield placeholder的颜色和位置

//继承uitextfield，重写这个方法
- (void) drawPlaceholderInRect:(CGRect)rect {
    [[UIColor blueColor] setFill];
    [self.placeholder drawInRect:rect withFont:self.font lineBreakMode:UILineBreakModeTailTruncation alignment:self.textAlignment];
}