1.编写主类

package com.sample.button;import android.content.Context;import android.content.res.TypedArray;import android.graphics.drawable.Drawable;import android.util.AttributeSet;import android.util.Log;import android.widget.CompoundButton;import com.example.buttonsample.R;public class MyButton extends CompoundButton {	public MyButton(Context context, AttributeSet attrs, int defStyle) {		super(context, attrs, defStyle);	}	private Drawable imgOFF;	private Drawable imgON;	public MyButton(Context context, AttributeSet attrs) {		super(context, attrs);		TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MyButton, 0, 0);		try {			imgOFF = a.getDrawable(R.styleable.MyButton_imgOFF);			imgON = a.getDrawable(R.styleable.MyButton_imgON);		} catch (Exception e) {			e.printStackTrace();		}		a.recycle();	}	public MyButton(Context context) {		super(context);	}	@Override	public void setChecked(boolean checked) {		super.setChecked(checked);		udpateDrawable();	}	private void udpateDrawable() {		if (this.isChecked()) {			Log.e(MyButton.class.getName(),"changing to imgON");			this.setBackgroundDrawable(imgON);		} else {			Log.e(MyButton.class.getName(),"changing to imgOFF");			this.setBackgroundDrawable(imgOFF);		}	}	@Override	protected void onFinishInflate() {		udpateDrawable();		super.onFinishInflate();	}}