Question

我有一个WKWebview加载基于Web的UI，我希望用户能够从他们的iCloud文档上传文件。我已授予正确的权限，我可以浏览iCloud文档。但是，当我选择文件或单击取消按钮时，以及取消我的WKWebview的父视图的文档选择器视图也被取消。

我试图跟踪解雇路径。我100％肯定我没有在我的观点上调用解雇功能。

有没有人知道什么是触发我的WKWebview容器上的解雇以及如何防止它？

Answer 1

我在使用WKWebView的Objective-C和iOS11上遇到了同样的问题，并使用此解决方法解决了它。您应该可以轻松地将其迁移到Swift：

我的WKWebView由一个直接扩展UIViewController的视图控制器拥有
在此视图控制器中添加此弱属性

@property (weak, nonatomic) UIDocumentPickerViewController *_Nullable docPickerPtr;

在同一视图控制器中覆盖这两个方法，这两个方法最初是UIViewController基类的一部分

- (void)presentViewController:(UIViewController *)viewControllerToPresent animated: (BOOL)flag completion:(void (^ __nullable)(void))completion
{
    if ([viewControllerToPresent isKindOfClass:[UIDocumentPickerViewController class]])
    {
        _docPickerPtr = (UIDocumentPickerViewController*)viewControllerToPresent;
    }

    [super presentViewController:viewControllerToPresent animated:flag completion:completion];
}

- (void)dismissViewControllerAnimated:(BOOL)flag
                           completion:(void (^)(void))completion
{
    if (_docPickerPtr != nil && self.presentedViewController == nil)
    {
        NSLog(@">>>>>>>>>>>>PREVENT FROM DOING 2nd DISMISS!");
    }
    else
    {    
        [super dismissViewControllerAnimated:flag completion:completion];
    }
}

我们所做的是：
1. 当我们要显示文档选择器时，保存一个指向UIDocumentPickerViewController的弱指针
2. dismissViewControllerAnimated：completition被调用两次。一旦presentViewController不是nil还没有杀死实际的文档选择器，并且当presentViewController消失但UIDocumentPickerViewController仍然存在时第二次出于未知原因。这个想法是为了防止第二次解雇传播到超级

Answer 2

UIDocumentPickerViewController中存在错误。

1）在视图控制器呈现UIDocumentPickerViewController的内部保存对UIDocumentPickerViewController的弱引用。（这通常最终成为UINavigationController，因此您可能需要继承UINavigationController来解决此问题。）

///Due to a bug in UIDocumentPickerViewController we need to stop the UIDocumentPickerViewController from dismissing this navigation controller. Or at least provide control. This is a weak reference to a UIDocumentPickerController that this controller presents
weak var documentPicker: UIDocumentPickerViewController?

2）在呈现UIViewController

的UIDocumentPickerViewController上覆盖这两个函数

//MARK: Overrides
override public func dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
    if self.presentedViewController == nil && self.documentPicker != nil {
        self.documentPicker = nil
    }else{
        super.dismiss(animated: flag, completion: completion)
    }
}

public override func present(_ viewControllerToPresent: UIViewController, animated flag: Bool, completion: (() -> Void)? = nil) {
    if viewControllerToPresent is UIDocumentPickerViewController {
        self.documentPicker = viewControllerToPresent as? UIDocumentPickerViewController
    }
    super.present(viewControllerToPresent, animated: flag, completion: completion)
}

现在来自UIDocumentPickerViewController的第二个电话不会驳回呈现UIViewController。

WKWebview的iCLoud文档选择器解除了容器视图

2 个答案: