UIPopoverPresentationController

前言

学习的时候遗漏了这个知识点，最近在做一个类微信、支付宝的 "+"号弹出浮窗的功能，发现了这个好用的东西～ 做个记录方便日后查阅
NS_CLASS_AVAILABLE_IOS(8_0) __TVOS_PROHIBITED //iOS8之后可用 @interface UIPopoverPresentationController : UIPresentationController

基本使用

/* Present the view controller using the popover style. */

// 每个viewController,都有一个modalPresentationStyle属性
TestViewController * test = [[TestViewController alloc]init];
test.preferredContentSize = CGSizeMake(300, 200);//设置浮窗的宽高
test.modalPresentationStyle = UIModalPresentationPopover;
 
 /* Get the popover presentation controller and configure it. */

//获取TestViewController的UIPopoverPresentationController
UIPopoverPresentationController * popover = [test popoverPresentationController];
popover.delegate = self;
popover.permittedArrowDirections = UIPopoverArrowDirectionUp;//设置箭头位置
popover.sourceView = self.popViewButton;//设置目标视图
popover.sourceRect = self.popViewButton.bounds;//弹出视图显示位置
popover.backgroundColor = [UIColor redColor];//设置弹窗背景颜色(效果图里红色区域)
[self presentViewController:test animated:YES completion:nil];

** UIPopoverPresentationControllerDelegate代理方法 **

/* 
For iOS8.0, the only supported adaptive presentation styles 
are UIModalPresentationFullScreen and UIModalPresentationOverFullScreen. */
// 设置 浮窗弹窗的推出样式，效果图中设置style为UIModalPresentationNone
-(UIModalPresentationStyle)adaptivePresentationStyleForPresentationController:
(UIPresentationController *)controller;

// Called on the delegate when the popover controller will dismiss the popover. Return NO to prevent the
// dismissal of the view.
// 点击浮窗背景popover controller是否消失
- (BOOL)popoverPresentationControllerShouldDismissPopover:(UIPopoverPresentationController *)popoverPresentationController;

// Called on the delegate when the user has taken action to dismiss the popover. This is not called when the popover is dimissed programatically.
// 浮窗消失时调用
- (void)popoverPresentationControllerDidDismissPopover:(UIPopoverPresentationController *)popoverPresentationController;

防止点击UIPopoverController区域外消失

默认情况下
只要UIPopoverController显示在屏幕上，UIPopoverController背后的所有控件默认是不能跟用户进行正常交互的
点击UIPopoverController区域外的控件，UIPopoverController默认会消失
要想点击UIPopoverController区域外的控件时不让UIPopoverController消失，解决办法是设置passthroughViews属性
@property (nonatomic, copy) NSArray *passthroughViews;
这个属性是设置当UIPopoverController显示出来时，哪些控件可以继续跟用户进行正常交互。这样的话，点击区域外的控件就不会让UIPopoverController消失了

写在最后

官网对UIPopoverPresentationController介绍
Human Interface Guidelines——Popovers