Objective

客观化

• I am trying to copy a text from a copy button inside a web page. The copy function itself is working fine when i open it using chrome, firefox and safari browser

Expected behavior:
After pressing the copy button, the text is copied into phone clipboard.
Current behavior:
After pressing the copy button, Flutter InAppWebView throwing error Uncaught (in promise) NotAllowedError: Write permission denied.

预期行为：按下复制按钮后，文本将复制到手机剪贴板中。当前行为：按下复制按钮后，Ffltter InAppWebView抛出错误未捕获(在Promise中)NotAlledError：写入权限被拒绝。

Step done to fix this error

修复此错误的步骤已完成

1. I have added android permission inside my Project > android > app > src > main >AndroidManifest.xml

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

2. PermissionRequestResponseAction is set to .GRANT, however, this callback is not called when i press on the copy button inside the web page

    androidOnPermissionRequest: (webViewController, origin, resources) async {
                      return PermissionRequestResponse(
                        resources: resources,
                        action: PermissionRequestResponseAction.GRANT,
                      );
                    },

3. javaScriptEnabled is set to true for Android, and its true by default

  InAppWebViewGroupOptions options = InAppWebViewGroupOptions(
      crossPlatform: InAppWebViewOptions(
          // allowFileAccessFromFileURLs: true,
          // javaScriptCanOpenWindowsAutomatically: true,
          // allowUniversalAccessFromFileURLs: true,
          javaScriptEnabled: true,
          useShouldOverrideUrlLoading: true,
          mediaPlaybackRequiresUserGesture: false),
      android: AndroidInAppWebViewOptions(
        useHybridComposition: true,
      ),
      ios: IOSInAppWebViewOptions(
        allowsInlineMediaPlayback: true,
      ));

Here are some related issue that have been asked, but still no solution for it:

以下是被问到的一些相关问题，但仍然没有解决方案：

1. webview_flutter: Uncaught (in promise) NotAllowedError: Write permission denied

   
   



2. https://github.com/pichillilorenzo/flutter_inappwebview/issues/678

   
   

How to solve for this error? Any help is much appreciated, thank you

如何解决这个错误？非常感谢您的任何帮助，谢谢

i also face this issue so i was resolve it by this way:

我也面临着这个问题，所以我通过这样的方式解决了它：

• i was try to add permission for android but it still not work and then i change to use java script to solve it maybe u can see it:

InAppWebView(
        initialUrlRequest: URLRequest(url: Uri.parse(url)),
        onLoadStop: (controller, url) {
          controller
            ..evaluateJavascript(
              source:
                  "document.getElementById('unwanted-element').remove();",
            )
            ..evaluateJavascript(
              source:
                  "document.body.style.background = 'linear-gradient(45deg, #3D1912, #701D1B)';",
            )
            ..evaluateJavascript(
                source:
                    'javascript:navigator.clipboard.writeText = (msg) => { return window.flutter_inappwebview?.callHandler("android", msg); }');
        },
        onWebViewCreated: (controller) async {
          if (Platform.isAndroid) {
            handleCopyText(controller, context, 'android');
          } else {
            handleCopyText(controller, context, 'copyText');
          }
        },
        initialOptions: InAppWebViewGroupOptions(
          crossPlatform: InAppWebViewOptions(
              disableVerticalScroll: true, disableHorizontalScroll: true),
        ),
      );

and then u can listen callback from webview to catch your text and save it to clipboard

然后你可以收听Webview的回调来捕捉你的文本并保存到剪贴板

Looks like the proper solution to handle such cases is what @ThanhOP mentioned, The only fix that is working is to handle that with JS injection.
Register a channel to get the data and send It to the FLutter side.

看起来处理这种情况的正确解决方案就是@ThanhOP提到的，唯一有效的修复方法是使用JS注入来处理。注册一个通道以获取数据并将其发送到颤振侧。

Note: I deleted extra code and added the required ones.
It works like a charm even with websites that had no problem.

注意：我删除了多余的代码，添加了必需的代码。即使在没有问题的网站上，它也像一个护身符一样起作用。

onLoadStop property looks like this:

OnLoadStop属性如下所示：

    onLoadStop: (controller, url) {
  controller.evaluateJavascript(
      source:
          'javascript:navigator.clipboard.writeText = (msg) => { return window.flutter_inappwebview?.callHandler("axs-wallet-copy-clipboard", msg); }');
  controller.addJavaScriptHandler(
    handlerName: 'axs-wallet-copy-clipboard',
    callback: (args) {
      copy(args);
    },
  );
},

copy function looks like this:

复制功能如下所示：

  void copy(List<dynamic> params) {
Clipboard.setData(ClipboardData(text: params[0]));
}