OnBackPressed不顯示警報

Question

我試圖重寫的onkeydown（）與onBackPressed（）方法，但警告對話框沿着方法，而不是不顯示它只是回到以前的intent.I嘗試幾個例子，但他們都沒有工作。

@Override 
    public boolean onKeyDown(int keyCode, KeyEvent event) { 
      if (keyCode == KeyEvent.KEYCODE_BACK) { 
     onBackPressed(); 

     } 

     return super.onKeyDown(keyCode, event); 
    } 

     @Override 
     public void onBackPressed() { 


     Log.d("confirm save method",""); 
     AlertDialog.Builder builder = new AlertDialog.Builder(this); 

      builder.setTitle(""); 
      builder.setMessage("Do you want to Save the Game ?"); 
      builder.setCancelable(false); 
       builder.setPositiveButton("YES", 
       new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, int which) { 
        finish(); 
        System.exit(0); 
       } 
      }); 

    builder.setNegativeButton("NO", 
      new DialogInterface.OnClickListener() { 
       public void onClick(DialogInterface dialog, int which) { 
        dialog.cancel(); 
       } 
      }); 

       AlertDialog alert = builder.create(); 
       alert.show(); 


      Log.d("confirm save method",""); 

}

Answer 1

@Override 
public void onBackPressed() { 
    AlertDialog.Builder builder = new AlertDialog.Builder(this); 
    builder.setMessage("Are you sure you want to exit?") 
      .setTitle("Exit Alert") 
      .setCancelable(false) 
      .setPositiveButton("Yes", new DialogInterface.OnClickListener() { 
       public void onClick(DialogInterface dialog, int id) { 

        //finishAffinity(); 
        finish(); //or do anything 
       } 
      }) 
      .setNegativeButton("No", new DialogInterface.OnClickListener() { 
       public void onClick(DialogInterface dialog, int id) { 
        dialog.cancel(); 
       } 
      }); 
    AlertDialog alert = builder.create(); 
    alert.show(); 
} 

試試這個代碼，同時還刪除您的onkeydown（）;

Answer 2

• 提示1：如果重寫onBackPressed，你不必重寫onKeyDown(int keyCode, KeyEvent event)。這很複雜。刪除這個方法（onKeyDown）可以解決這個問題。

• 提示2：return true中斷此鍵事件。

  @Override 
  public boolean onKeyDown(int keyCode, KeyEvent event) { 
       if (keyCode == KeyEvent.KEYCODE_BACK) { 
       alertAialog(); 
       return true; 
       } 
  
      return super.onKeyDown(keyCode, event); 
  } 
  private void alertDialog(){ 
  ... 
  }