从 UIViewController 中删除子视图

Question

我正在向主视图添加一个子视图，但我无法从该视图中删除它。

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];

这里我在视图中添加了一个按钮，然后当按下按钮时它就会消失`-

(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];
}

我试过了：

[nextView.view removeFromSuperView];

[nextView.presentedViewController removeFromParentViewController];

但我不知道我还能做什么：S

如果您想了解更多信息，nextView 是一个 300x100 大小的 UIViewController。我想展示它，然后在我按下按钮时将其移除，仅此而已。

如果有人可以帮助我，我会很棒。

谢谢

Answer 1

您正在创建不同的参考，然后您尝试将其从其超级视图中删除，而根本没有添加。我将尝试解释： 1. 当您将nextView.view 添加到self.view 时，您已经创建了一个这样的实例

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

2。当您尝试删除它时，不是引用上面的实例，而是在您的 waitForNextView 方法中再次创建一个全新的实例

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

然后您尝试将其删除。请注意，nextView 的最后一个实例尚未添加到任何地方，这就是您的代码不起作用的原因。

为了工作，您应该参考您添加到self.view 的第一个参考。请调整您的代码如下所示

在你的ViewController.m

@interface ViewController()
{
 NextViewController *nextView;
}

添加您的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];

最后在你的 IBAction 方法中

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

Answer 2

这里的问题是你将按钮作为子视图添加到nextView的视图中，所以删除nextView的视图是行不通的。

如果给按钮添加标签，则可以使用标签检索子视图。例如。当你定义你的按钮时：

[stayButton setTag:1];

然后在waitForNextView方法中，可以像这样获取控件：

UIButton *stayButton = (UIButton*)[nextView.view viewWithTag:1];
[stayButton removeFromSuperView];

Answer 3

在方法dismissView2中使用此代码

for (UIView *subview in view.subviews ){
    [subview removeFromSuperview];
}