ios:UIAlertView自动消失

在写程序的过程中用到很多提示的信息，于是非常自然地就要使用UIAlertView控件。但是这些提示的信息有时候只需提示就行，不用操作，那么此时就要这个提示框自动消失就OK了。 UIAlertView弹出后2s让其自动消失，两种方法： (1)结合NSTimer

定义UIAlertView *baseAlert;

- (void) performDismiss: (NSTimer *)timer {

[baseAlert dismissWithClickedButtonIndex:0 animated:NO];//important

[baseAlert release];

baseAlert = NULL;

}

- (void) presentSheet {

baseAlert = [[UIAlertView alloc]  initWithTitle:@"Alert" message:@"\nMessage Message Message "  delegate:self cancelButtonTitle:nil                               otherButtonTitles: nil];

[NSTimer scheduledTimerWithTimeInterval:2.0f target:self selector: @selector(performDismiss:)  userInfo:nil repeats:NO];

[baseAlert show]; }

(2)使用PerformSelector：withObject：afterDelay：方法

- (void) dimissAlert:(UIAlertView *)alert {

if(alert)     {

[alert dismissWithClickedButtonIndex:[alert cancelButtonIndex] animated:YES];

[alert release];

}

}

- (void)showAlert{

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"title" message:@"message" delegate:nil  cancelButtonTitle:nilotherButtonTitles:nil];

[alert show];

[self performSelector:@selector(dimissAlert:) withObject:alert afterDelay:2.0];

}