iOS开发中的奇葩技巧

TableView不显示没内容的Cell怎么办?

类似这种,我不想让下面那些空的显示.

很简单.

 

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

 

加完这句之后就变成了这样.

2 、自定义了leftBarbuttonItem左滑返回手势失效了怎么办?

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

3、ScrollView莫名其妙不能在viewController划到顶怎么办?

 

self.automaticallyAdjustsScrollViewInsets = NO;

4、键盘事件写的好烦躁,都想摔键盘了,怎么办?

 

     使用IQKeyboardManager(github上可搜索）

5、为什么我的app老是不流畅,到底哪里出了问题?

如图

 

这个神器叫做:KMCGeigerCounter,快去github搬运吧.

6、怎么在不新建一个Cell的情况下调整separaLine的位置?

 

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

 

7、怎么点击self.view就让键盘收起,需要添加一个tapGestures么?

 

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

 

 

8、怎么给每个ViewController设定默认的背景图片?

     使用基类啊,少年。

9、想在代码里改在xib里添加的layoutAttributes,但是怎么用代码找啊?

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

10、怎么像safari一样滑动的时候隐藏navigationbar?

navigationController.hidesBarsOnSwipe = Yes;

11、导航条返回键带的title太讨厌了,怎么让它消失!

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

12、CoreData用起来好烦,语法又臭又长,怎么办?

 使用 MagicRecord

13、CollectionView 怎么实现tableview那种悬停的header?

使用 CSStickyHeaderFlowLayou

14、能不能只用一个pan手势来代替UISwipegesture的各个方向?

- (void)pan:(UIPanGestureRecognizer *)sender { typedef NS_ENUM(NSUInteger, UIPanGestureRecognizerDirection) { UIPanGestureRecognizerDirectionUndefined, UIPanGestureRecognizerDirectionUp, UIPanGestureRecognizerDirectionDown, UIPanGestureRecognizerDirectionLeft, UIPanGestureRecognizerDirectionRight }; static UIPanGestureRecognizerDirection direction = UIPanGestureRecognizerDirectionUndefined; switch (sender.state) { case UIGestureRecognizerStateBegan: { if (direction == UIPanGestureRecognizerDirectionUndefined) { CGPoint velocity = [sender velocityInView:recognizer.view]; BOOL isVerticalGesture = fabs(velocity.y) > fabs(velocity.x); if (isVerticalGesture) { if (velocity.y > 0) { direction = UIPanGestureRecognizerDirectionDown; } else { direction = UIPanGestureRecognizerDirectionUp; } } else { if (velocity.x > 0) { direction = UIPanGestureRecognizerDirectionRight; } else { direction = UIPanGestureRecognizerDirectionLeft; } } } break; } case UIGestureRecognizerStateChanged: { switch (direction) { case UIPanGestureRecognizerDirectionUp: { [self handleUpwardsGesture:sender]; break; } case UIPanGestureRecognizerDirectionDown: { [self handleDownwardsGesture:sender]; break; } case UIPanGestureRecognizerDirectionLeft: { [self handleLeftGesture:sender]; break; } case UIPanGestureRecognizerDirectionRight: { [self handleRightGesture:sender]; break; } default: { break; } } break; } case UIGestureRecognizerStateEnded: { direction = UIPanGestureRecognizerDirectionUndefined; break; } default: break; } }

15、拉伸图片的时候怎么才能让图片不变形？

 

UIImage *image = [[UIImage imageNamed:@"xxx"] stretchableImageWithLeftCapWidth:10 topCapHeight:10]；

2）

16、怎么播放GIF的时候这么卡，有没有好点的库？

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

17、怎么一句话添加上拉刷新？

https://github.com/samvermette/SVPullToRefresh

 

[tableView addPullToRefreshWithActionHandler:^{ // prepend data to dataSource, insert cells at top of table view // call [tableView.pullToRefreshView stopAnimating] when done } position:SVPullToRefreshPositionBottom];

18、怎么把tableview里cell的小对勾的颜色改成别的颜色？

_mTableView.tintColor = [UIColor redColor];

 

 

19、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，怎么办？

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

20、怎么把我的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;

21、怎么改变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]; }