ios - 从 UIViewController 中删除 subview

Question

我正在向主视图添加一个 subview ，但无法从该 View 中删除它。

NextViewController *nextView = [[NextViewController alloc] init];

nextView.transitioningDelegate = self;
nextView.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self.presentedViewController.view addSubview:nextView.view];
nextView.view.frame = CGRectMake(724, 80, 300, 150);

UIButton *stayButton = [[UIButton alloc] initWithFrame:CGRectMake(101, 94, 90, 49)];
[stayButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[stayButton setTitle:@"Detener" forState:UIControlStateNormal];
[stayButton addTarget:self
           action:@selector(waitForNextView)
 forControlEvents:UIControlEventTouchUpInside];
[nextView.view addSubview:stayButton];
stayButton.titleLabel.font = [UIFont systemFontOfSize:25];
[stayButton setTitleColor:[UIColor colorWithRed:(255/255.0) green:(255/255.0) blue:(255/255.0) alpha:1] forState:UIControlStateNormal];

这里我在 View 中添加一个按钮，然后当按下按钮时它就会出现`-

(void)waitForNextView{
    transition = NO;
    NextViewController *nextView = [[NextViewController alloc] init];
    SectionViewController *sectionView = [[SectionViewController alloc]init];
    [self.locationManager stopRangingBeaconsInRegion:self.beaconRegion];
    actualSection = 0;
    [NSTimer scheduledTimerWithTimeInterval:10.0 target:self selector:@selector(dismissView2) userInfo:nil repeats:NO];
}

我尝试过:

[nextView.view removeFromSuperView];

[nextView.presentedViewController removeFromParentViewController];

但我不知道还能做什么:S

如果你想了解更多信息，nextView是一个300x100大小的UIViewController。我想展示它，然后在按下按钮时将其删除，仅此而已。

如果有人能帮助我，我会很好。

谢谢

Answer 1

您正在创建不同的引用，然后尝试将其从其 super View 中删除，而根本不添加它。我将尝试解释: 1. 当您将 nextView.view 添加到 self.view 时，您已经创建了一个像这样的实例

NextViewController *nextView = [[NextViewController alloc] init];

2.当您尝试删除它时，您不是引用上面的实例，而是在 waitForNextView 方法中再次创建一个全新的实例，就像这样

 NextViewController *nextView = [[NextViewController alloc] init];

然后你试图删除它。请注意，nextView 的最后一个实例尚未添加到任何位置，这就是您的代码无法工作的原因。

为了工作，您应该引用您添加到 self.view 中的第一个引用。请调整您的代码，如下所示

在你的ViewController.m

@interface ViewController()
{
 NextViewController *nextView;
}

添加viewController时

nextView = [[NextViewController alloc] init];

nextView.transitioningDelegate = self;
nextView.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self.presentedViewController.view addSubview:nextView.view];
nextView.view.frame = CGRectMake(724, 80, 300, 150);

UIButton *stayButton = [[UIButton alloc] initWithFrame:CGRectMake(101, 94, 90, 49)];
[stayButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[stayButton setTitle:@"Detener" forState:UIControlStateNormal];
[stayButton addTarget:self
           action:@selector(waitForNextView)
 forControlEvents:UIControlEventTouchUpInside];
[nextView.view addSubview:stayButton];
stayButton.titleLabel.font = [UIFont systemFontOfSize:25];
[stayButton setTitleColor:[UIColor colorWithRed:(255/255.0) green:(255/255.0) blue:(255/255.0) alpha:1] forState:UIControlStateNormal];

最后在您的 IBAction 方法中

-(void)waitForNextView{
    transition = NO;
    [self.locationManager stopRangingBeaconsInRegion:self.beaconRegion];
    actualSection = 0;
    [nextView removeFromSuperview];
}