我打算用什么代码？

如果我将按钮更改为ImageButtons，我可以使用哪些代码，我可以使用图片而不是字母。这是我的代码仅使用按钮。

What codes am i going to use if i will change the buttons here into ImageButtons where i can play with pictures and not letters. Here's my code using Buttons only.

btn1 = (Button) findViewById(R.id.btn1);
       btn2 = (Button) findViewById(R.id.btn2);
       btn3 = (Button) findViewById(R.id.btn3);
       btn4 = (Button) findViewById(R.id.btn4);
       btn5 = (Button) findViewById(R.id.btn5);
       btn6 = (Button) findViewById(R.id.btn6);

       btn1.setOnClickListener(new View.OnClickListener() {
           public void onClick(View v) {
               CheckButton(btn1, btn2);
               CheckButton(btn1, btn4);

           }
           });
           btn2.setOnClickListener(new View.OnClickListener() {
           public void onClick(View v) {
               CheckButton(btn2, btn1);
               CheckButton(btn2, btn3);
               CheckButton(btn2, btn5);
           }
           });
           .........and so on.
   }

        private void CheckButton(final Button btn1, final Button btn2) {
                   if (btn2.getText().equals(""))
                   {
                       btn2.setText(btn1.getText().toString());
                       btn1.setText("");
                   }


            }

这是我的图像按钮代码，它有.setBackground（null）的问题。

Here's my codes for Image Buttons which has problems with ".setBackground(null)".

ibtn1 = (ImageButton) findViewById(R.id.ibtn1);
       ibtn2 = (ImageButton) findViewById(R.id.ibtn2);

       ibtn1.setOnClickListener(new View.OnClickListener() {
           public void onClick(View v) {
               CheckiButton(ibtn1, ibtn2);


           }
           });
       ibtn2.setOnClickListener(new View.OnClickListener() {
           public void onClick(View v) {
               CheckiButton(ibtn2, ibtn1);


           }
           });
private void CheckiButton(final ImageButton ibtn1, final ImageButton ibtn2) {
                   if (ibtn2.getBackground().equals(""))
                   {
                       ibtn2.setBackground(ibtn1.getBackground());
                       ibtn1.setBackgroundResource("");
                   }


            }