警報對話框無法添加窗口錯誤

Question

我正在嘗試使用此代碼從RecyclerView.Adapter創建AlertDialog

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(new ContextThemeWrapper(context, R.style.AppTheme));
alertDialogBuilder.setView(R.layout.reserve_dialog);
alertDialogBuilder.create();
alertDialogBuilder.show();

但我在logcat中遇到此錯誤：

Theme: themes:{}
android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application

怎么了？

Answer 1

代替getApplicationContext（），只需使用ActivityName.this即可。

   AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(new  ContextThemeWrapper(activity, R.style.AppTheme));
   alertDialogBuilder.setView(R.layout.reserve_dialog);
   alertDialogBuilder.create();
   if(!isFinishing()){
    alertDialogBuilder.show();
   }

Answer 2

您正在傳遞context.getApplicationContext（）

代替此通過活動上下文

    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(new ContextThemeWrapper(MainActivity.this, R.style.AppTheme));
    alertDialogBuilder.setView(R.layout.reserve_dialog);
    alertDialogBuilder.create();
    alertDialogBuilder.show();

Answer 3

刪除getApplicationContext（）並傳遞活動上下文。

Answer 4

內部新對話（youractivity.this，樣式）

希望它能解決

Answer 5

如果要在RecylerView.Adapter內部創建對話框，請在Adapter的構造函數中傳遞活動對象，並在創建構建器時使用該對象本身-

    if (!activity.isFinishing()) {
      AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(new ContextThemeWrapper(activity, R.style.AppTheme));
      alertDialogBuilder.setView(R.layout.reserve_dialog);
      alertDialogBuilder.create();
      alertDialogBuilder.show();
    }

當您在非活動類中顯示對話框時，則必須將活動作為參數傳遞。