尝试在网页中加载相机时，Webview崩溃

Question

我有一个webview，可以加载允许用户上传图片的页面。当用户选择“拍照”选项时，应用程序会崩溃，并显示以下警告。

警告：尝试在视图不在窗口层次结构中的<UIImagePickerController: 0x1563d8000>上显示<UINavigationController: 0x156b4c400>！

以下是用于加载webview的代码

WebViewController *webViewController = [[WebViewController alloc] initWithUrlString:urlString];
[viewController showViewControllerFullScreen:webViewController];

- (void)showViewControllerFullScreen:(UIViewController *)viewController {
    UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
    [self.view.window.rootViewController presentViewController:navigationController animated:YES completion:nil];
}

为什么UINavigation Controller在用于呈现Web视图时不属于窗口层次结构？

Answer 1

请设置以下行

  self.window.rootViewController = navigationController;

参考

UIImagePickerController on UINavigationController whose view is not in the window hierarchy

iOS: Warning “attempt to present ViewController whose view is not in the window hierarchy”