public void onClick(View v) {
   if(v == ButtonName) {
     ButtonName.setImageResource(R.drawable.ImageName);
   }
}

或者，使用XML文件：

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_pressed="true"
   android:drawable="@drawable/login_selected" /> <!-- pressed -->
  <item android:state_focused="true"
   android:drawable="@drawable/login_mouse_over" /> <!-- focused -->
  <item android:drawable="@drawable/login" /> <!-- default -->
</selector>

在OnClick中，只需添加以下代码：

ButtonName.setBackgroundDrawable(getResources().getDrawable(R.drawable.ImageName));