22个iOS开发的小技巧

结合自身的实践开发经验总结出了22个iOS开发的小技巧，以非常欢乐的语调轻松解决开发过程中所遇到的各种苦逼难题，光读着便已忍俊不禁。 

 1. TableView不显示没内容的Cell怎么办？  类似于图1，我不想让下面的那些空显示。很简单，添加“self.tableView.tableFooterView = [[UIView alloc] init];”试过都说好，加完这句之后就变成了

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. 键盘事件写得好烦躁，都想摔键盘了怎么办？ 买个结实的键盘；  使用IQKeyboardManager（GitHub上可搜索），用完之后腰也不疼了，腿也不酸了。

  5. 为什么我的App老是不流畅， 这个神器叫做：KMCGeigerCounter ，快去GitHub上搬运吧。

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，但该怎么用代码找？ 像拉Button一样地拉你的约束，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？ MagicRecord

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

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: {}