iOS之UIAlertView点击窗口之外区域关闭

原文地址：传送门

弹出一个UIAlertView，然后点击窗口之外的区域来关闭UIALertView，代码如下：

[objc]  view plain  copy

1. - (IBAction)showAlert:(id)sender {  
2.   
3.   alert = [[UIAlertView alloc] initWithTitle:@"测试"  
4.                                      message:@"点击四周的区域我就消失"  
5.                                     delegate:nil  
6.                            cancelButtonTitle:@"确定"  
7.                            otherButtonTitles:nil];  
8.   [alert show];  
9.   recognizerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapBehind:)];  
10.   
11.   [recognizerTap setNumberOfTapsRequired:1];  
12.   recognizerTap.cancelsTouchesInView = NO;   
13.   [[UIApplication sharedApplication].keyWindow addGestureRecognizer:recognizerTap];  
14. }  
15.   
16. - (void)handleTapBehind:(UITapGestureRecognizer *)sender {  
17.   if (sender.state == UIGestureRecognizerStateEnded){  
18.     CGPoint location = [sender locationInView:nil];  
19.     if (![alert pointInside:[alert convertPoint:location fromView:alert.window] withEvent:nil]){  
20.       [alert.window removeGestureRecognizer:sender];  
21.       [alert dismissWithClickedButtonIndex:0 animated:YES];  
22.     }  
23.   }  
24. }