android - 按下后退按钮时，对话框显示两次

在代码中，当我按下后退按钮时，对话框显示两次。有谁能告诉我如何只得到一次对话吗？

public boolean onKeyDown(int keyCode, KeyEvent event)
    {
        if ((keyCode == KeyEvent.KEYCODE_BACK))
        {
            onBackPressed();
        }
        return super.onKeyDown(keyCode, event);
         }

public void onBackPressed()
    {

            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("Do you want to save configuration?");
            builder.setPositiveButton
                           ("Yes", new DialogInterface.OnClickListener()
            {
                public void onClick(DialogInterface dialog, int id)
                {
                //here saveConfiguration is boolean type
                    if (saveConfiguration())

                                              {
                        dialog.dismiss();
                        finish();

                    }
                    else
                    {
                        dialog.dismiss();
                    }

                }
            });
            builder.setNegativeButton("No", new DialogInterface.OnClickListener()
            {
                public void onClick(DialogInterface dialog, int id)
                {
                    dialog.dismiss();
                    finish();
                }
            });
            builder.show();
    }



}

最佳答案

您的对话框将出现两次，因为它将消耗来自back key的两个事件，即key down和key up。限制他们中的任何一个。

             if (event.getAction() != KeyEvent.ACTION_DOWN)
 {

      /* Now call onBackPressed method here */
 }