UIView-tag

   UIView *v =[[UIViewalloc] initWithFrame:CGRectMake(10,20, 320, 30)];

    v.tag =200;

    v.backgroundColor = [UIColorblackColor];

    [self.windowaddSubview:v];

    

    [vrelease];

    //>的所有对象权已经交给window

    

    return YES;

}

-(void)click:(UIButton *)b

{

    NSLog(@"tag is %d",b.tag);

    //在父视图中寻找子视图tag值为N的UIView方法

   UIView *v =[self.windowviewWithTag:200];

    

    NSLog(@"v is %@",v);

}