Android自定义button的兑现，未选中，按下，选中效果

package com.test.TestButton;import android.app.Activity;import android.content.Context;import android.graphics.drawable.Drawable;import android.graphics.drawable.StateListDrawable;import android.os.Bundle;import android.view.View;import android.widget.Button;public class TestButton extends Activity {   @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        Integer[] mButtonState = { R.drawable.defaultbutton,                R.drawable.focusedpressed, R.drawable.pressed };        Button mButton = (Button) findViewById(R.id.button);        MyButton myButton = new MyButton(this);        mButton.setBackgroundDrawable(myButton.setbg(mButtonState));    }    class MyButton extends View {        public MyButton(Context context) {            super(context);        }        //以下这个方法也可以把你的图片数组传过来，以StateListDrawable来设置图片状态，来表现button的各中状态。未选 	中，按下，选中效果。        public StateListDrawable setbg(Integer[] mImageIds) {            StateListDrawable bg = new StateListDrawable();            Drawable normal = this.getResources().getDrawable(mImageIds[0]);            Drawable selected = this.getResources().getDrawable(mImageIds[1]);            Drawable pressed = this.getResources().getDrawable(mImageIds[2]);            bg.addState(View.PRESSED_ENABLED_STATE_SET, pressed);            bg.addState(View.ENABLED_FOCUSED_STATE_SET, selected);            bg.addState(View.ENABLED_STATE_SET, normal);            bg.addState(View.FOCUSED_STATE_SET, selected);            bg.addState(View.EMPTY_STATE_SET, normal);            return bg;        }    }}