ios10，ios9 中UIPopoverController

在ipad开发中，ios9中的UIPopoverController 运用的非常多，它继承的不是ViewController 而是NSObject,这就说它的显示依靠其他视图控制器，但是在ios10中它被废弃了用p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 18.0px STXinwei; color: #00afca}span.s1 {font-variant-ligatures: no-common-ligatures}

UIPopoverPresentationController替代，虽然可以使用作为程序员跟着Apple公司走是没错的，实现内容和显示大致如下：

QQ20161225-0.png

iOS9 初始化代码：

  UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
  UIViewController *controller = [storyboard instantiateViewControllerWithIdentifier:@"PopContentController"];
  UIPopoverController *popVc = [[UIPopoverController alloc] initWithContentViewController:controller];
  [popVc presentPopoverFromBarButtonItem:self.leftButton permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

iOS10 的使用

 UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    UIViewController *controller = [storyboard instantiateViewControllerWithIdentifier:@"PopContentController"];

    
    controller.modalPresentationStyle = UIModalPresentationPopover;
    [self presentViewController:controller animated:YES completion:nil];
    
    // configure the Popover presentation controller
    UIPopoverPresentationController *popController = [controller popoverPresentationController];
    popController.permittedArrowDirections = UIPopoverArrowDirectionAny;
    popController.barButtonItem = self.leftButton;
    popController.delegate = self;