从 UIWindow 中移除 UIViewController 的视图

Question

当用户单击添加按钮时，我正在 UIWindow 上添加视图。现在，如果用户再次单击添加按钮，我想先删除该视图并再次添加它。

我已经使用此代码在 UIWindow 上添加视图：

ProgressVC *vc = [[UIStoryboard storyboardWithName:@"Main" bundle:nil] instantiateViewControllerWithIdentifier:@"IDProgressVC"];
[[[[UIApplication sharedApplication] delegate]window] addSubview:vc.view];

对于删除我试过这个代码：

[vc.view removeFromSuperview];
[[[[UIApplication sharedApplication] delegate]window] setNeedsLayout];
vc = nil;

任何帮助将不胜感激。

Answer 1

确保 vc 是同一个对象，没有区别。

我的意思是，当您添加 vc.view 时，您会分配和初始化对象，当您删除时，您会再次分配和初始化，然后两者都是相同 class.[=12= 的不同实例]

所以最好声明实例变量或者属性像，

ProgressVC *vc 并只分配一次并从 window 添加或删除此 vc。

我认为这可能会解决您的问题。

Answer 2

试试这个

// Make this global property

@property(nonatomic, strong) UIView * currentView;

//store the view in gloabal property
ProgressVC *vc = [[UIStoryboard storyboardWithName:@"Main" bundle:nil] instantiateViewControllerWithIdentifier:@"IDProgressVC"];
currentView = vc.view;
[[[[UIApplication sharedApplication] delegate]window] addSubview:currentView];

//remove it 
[currentView removeFromSuperview];
[[[[UIApplication sharedApplication] delegate]window] setNeedsLayout];
currentView = nil;

Answer 3

在Swift3.2

let storybord = UIStoryboard.init(name: "Main", bundle: nil)
let appDelegate = UIApplication.shared.delegate as! AppDelegate

let vc = storybord.instantiateViewController(withIdentifier: "IDProgressVC")
               as IDProgressVC

currentVC = vc.view

appDelegate.window?.addSubview(currentVC!)

// Remove it
currentVC?.removeFromSuperview()

appDelegate.window?.setNeedsLayout()

currentVC = nil

从 UIWindow 中移除 UIViewController 的视图

Remove view of UIViewController from UIWindow

objective-c

uiwindow

ios