【代码笔记】iOS-UIAlertView自动关闭

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController
<UIAlertViewDelegate>

@end

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.

//alert
UIAlertView *alert=[[UIAlertView alloc]initWithTitle:nil message:@"一个可以自动关闭的Alert窗口" delegate:self cancelButtonTitle:nil otherButtonTitles:nil, nil];
[alert show];

//显示框
UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
indicator.backgroundColor=[UIColor redColor];
indicator.center = CGPointMake(alert.bounds.size.width/2,  alert.bounds.size.height-40.0);
[indicator startAnimating];

[alert insertSubview:indicator atIndex:0];

//定时器
[NSTimer scheduledTimerWithTimeInterval:3.0f target:self selector:@selector(dismissAlert:) userInfo:[NSDictionary dictionaryWithObjectsAndKeys:alert, @"alert", @"testing ", @"key" ,nil]  repeats:NO];
}
//alert 自动消失
-(void) dismissAlert:(NSTimer *)timer{

UIAlertView *alert = [[timer userInfo]  objectForKey:@"alert"];
[alert dismissWithClickedButtonIndex:0 animated:YES];

}