<android="http://schemas.android.com/apk/res/Android">

   android:drawable="@drawable/temp2" />

<http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello"
    />
 <android:drawableTop="@drawable/shouru"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="@string/button"
 android:background="@drawable/selector"/>

 方法二
1.布局文件main.xml
[code]
<http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello"
    />
 <android:id="@+id/button"
 android:drawableTop="@drawable/shouru"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="@string/button"
 android:background="@drawable/temp4"/>

   Button button = (Button) this.findViewById(R.id.button);
   button.setOnTouchListener(new Button.OnTouchListener(){
   @Override
   public boolean onTouch(View v, MotionEvent event) {
    if(event.getAction() == MotionEvent.ACTION_DOWN){  
                    v.setBackgroundResource(R.drawable.temp1);  
                    Log.i("TestAndroid Button", "MotionEvent.ACTION_DOWN");
                }  
                else if(event.getAction() == MotionEvent.ACTION_UP){  
                    v.setBackgroundResource(R.drawable.temp2);
                    Log.i("TestAndroid Button", "MotionEvent.ACTION_UP");
                }
    return false;
   }
  });