在android webview中的JS確認框不工作

Question

使用此代碼加載url.Url在android &桌面瀏覽器中工作正常。 我已經編寫Android代碼來顯示android中的確認框。它是由在控制檯給錯誤的工作在華爲設備顯示在Nexus和三星的設備很好，但沒有確認框

"Uncaught TypeError: Cannot call method 'querySelector' of null", source: http://abc/build/js/frontend-abc.js (16683)

private class WebViewChromeClient extends WebChromeClient { 
     @Override 
     public boolean onJsAlert(WebView view, String url, String message, final android.webkit.JsResult result) { 
      new AlertDialog.Builder(context) 
        .setTitle(getString(R.string.str_confirmation_title)) 
        .setMessage(message) 
        .setPositiveButton(getString(R.string.str_ok), 
          new AlertDialog.OnClickListener() { 
           public void onClick(DialogInterface dialog, int which) { 
            result.confirm(); 
           } 
          }).setCancelable(false).create().show(); 

      return true; 
     } 

     @Override 
     public boolean onJsConfirm(WebView view, String url, String message, final JsResult result) { 
      new AlertDialog.Builder(context) 
        .setTitle(getString(R.string.str_confirmation_title)) 
        .setMessage(message) 
        .setPositiveButton(getString(R.string.str_ok), 
          new DialogInterface.OnClickListener() { 
           public void onClick(DialogInterface dialog, int which) { 
            result.confirm(); 
           } 
          }).setNegativeButton(getString(R.string.str_cancel), 
        new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, int which) { 
          result.cancel(); 
         } 
        }).create().show(); 
      return true; 
     } 

     @Override 
     public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, final JsPromptResult result) { 
      final LayoutInflater factory = LayoutInflater.from(context); 
      final View v = factory.inflate(R.layout.layout_alertdialog, null); 
      ((TextView) v.findViewById(R.id.tv_messagealert)).setText(message); 
      showJSPromptAlert(v, result); 
      return true; 
     } 
} 

private void showJSPromptAlert(View v, final JsPromptResult result) { 
     AlertDialog.Builder builder = new AlertDialog.Builder(context) 
       .setTitle(getString(R.string.str_confirmation_title)) 
       .setView(v) 
       .setPositiveButton(android.R.string.ok, 
         new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, int whichButton) { 
           result.confirm(getString(R.string.str_ok)); 
          } 
         }) 
       .setNegativeButton(android.R.string.cancel, 
         new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, int whichButton) { 
           result.cancel(); 
          } 
         }) 
       .setOnCancelListener(
         new DialogInterface.OnCancelListener() { 
          public void onCancel(DialogInterface dialog) { 
           result.cancel(); 
           dialog.cancel(); 
          } 
         }); 
     alert11 = builder.create(); 
     alert11.show(); 
    } 
WebView wvContainer = (WebView) findViewById(R.id.wv_container); 
private void loadUrl(String url) { 
     wvContainer.setInitialScale(1); 
     wvContainer.setWebViewClient(new MyBrowser()); 
     adjustWebViewSettings(); 
     wvContainer.canGoBack(); 
     adjustWebViewForLatestVersion(); 
     wvContainer.setWebChromeClient(new WebViewChromeClient()); 
     wvContainer.loadUrl(url); 
    } 

    private void adjustWebViewSettings() { 
     wvContainer.getSettings().setJavaScriptEnabled(true); 
     wvContainer.getSettings().setSupportZoom(true); 
     wvContainer.getSettings().setAllowContentAccess(true); 
     wvContainer.getSettings().setJavaScriptCanOpenWindowsAutomatically(true); 
     wvContainer.getSettings().setSupportMultipleWindows(true); 
     wvContainer.getSettings().setDomStorageEnabled(true); 
     wvContainer.getSettings().setAppCacheEnabled(true); 
     wvContainer.getSettings().setUseWideViewPort(true); 
     if (Build.VERSION.SDK_INT >= 21) { 
      wvContainer.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW); 
     } 
    } 

    private void adjustWebViewForLatestVersion() { 
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) { 
      wvContainer.getSettings().setAllowUniversalAccessFromFileURLs(true); 
      wvContainer.getSettings().setAllowFileAccessFromFileURLs(true); 
      wvContainer.getSettings().setAllowFileAccess(true); 
      wvContainer.setLayerType(View.LAYER_TYPE_SOFTWARE, null); 
     } 
    } 

Answer 1

"Uncaught TypeError: Cannot call method 'querySelector' of null"基本上意味着，在網頁視圖JS代碼試圖訪問的東西，是querySelector對象解釋爲空。

Null是一個基元，沒有屬性。所以你可能有一些編程錯誤，它依賴於A的存在來填充B，但A似乎不存在（querySelector是文檔或元素中的一種方法）。

怎麼辦

嘗試獲取設備錯誤的JS堆棧跟蹤的明白，爲什麼這應該提供querySelector（文檔或元素）的事情是零。然後解決這個問題，看看是否一切照好...

可能的原因

• 當代碼是調用它的方法
• 設備特定的代碼壞了
• 墨菲的文件沒有完全加載Law ...