ios - 以编程方式删除 subview

Question

我在 appdelegate 的 didReceiveRemoteNotification: 方法中得到了这段代码

我想知道如何使用延迟删除此 subview ，假设 subview 显示来自推送通知的信息，但我希望它们在 3.5 秒后消失(延迟 2)

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {

    NSLog(@"remote notification: %@",[userInfo description]);
    NSDictionary *apsInfo = [userInfo objectForKey:@"aps"];
    NSString *alert = [apsInfo objectForKey:@"alert"];
    NSLog(@"Received Push Alert: %@", alert);

    NSString *sound = [apsInfo objectForKey:@"sound"];
    NSLog(@"Received Push Sound: %@", sound);
    AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);

    NSString *badge = [apsInfo objectForKey:@"badge"];
    NSLog(@"Received Push Badge: %@", badge);
    application.applicationIconBadgeNumber = [[apsInfo objectForKey:@"badge"] integerValue];
    // Create the UILabel instance

    CGRect myFrame = CGRectMake(0, 20, 320, 50);
    UIView *myView = [[UIView alloc] initWithFrame:myFrame];
    myView.backgroundColor = [UIColor blueColor];
    [self.window addSubview:myView];
    [myView release];

    UILabel *aLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 35, 300, 20)];
    [aLabel setText:alert];
    [self.window addSubview:aLabel];
    [aLabel release];

    NSString *path = [[NSBundle mainBundle] pathForResource:@"sound"ofType:@"mp3"];

    AVAudioPlayer* theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];

    [theAudio play];
    //SONAR//
    [self performSelector:@selector(delay2) withObject:nil afterDelay:3.5];
}

-(void)delay2 {

    NSString *path = [[NSBundle mainBundle] pathForResource:@"sound"ofType:@"mp3"];

    AVAudioPlayer* theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];

    [theAudio play];
}

Answer 1

您可以使用 UIView 的 removeFromSuperview 实例方法。在为所有窗口设置标签添加 View 时。并在 delay2 方法中使用 tag 和 removeFromSuperview 方法删除它们。

CGRect myFrame = CGRectMake(0, 20, 320, 50);
UIView *myView = [[UIView alloc] initWithFrame:myFrame];
myView.backgroundColor = [UIColor blueColor];
[myView setTag:999];
[self.window addSubview:myView];
[myView release];

UILabel *aLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 35, 300, 20)];
[aLabel setText:alert];
[aLabel setTag:999];
[self.window addSubview:aLabel];
[aLabel release];


-(void)delay2 {

for(UIView *subView in window.subviews)
{
    if(subView.tag == 999)
        [subView removeFromSuperview];
}