自定义开关ToggleButton

package com.example.test;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

//------------MainActivity中----------------------

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //找到控件
        TooggleButtonCustom buttonCustom=(TooggleButtonCustom) findViewById(R.id.custom_button);
            //设置背景图片
             buttonCustom.setBackGroundPic(R.drawable.switch_background);
             //设置前边的图片
             buttonCustom.setForePic(R.drawable.slide_button_background);
             //设置默认状态
             buttonCustom.setState(false);

    }

}

//-------------自定义控件TooggleButtonCustom------继承view--------------------

package com.example.test;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

public class TooggleButtonCustom extends View{
   private Bitmap backBitmap;//背景图片
   private Bitmap foreBitmap;//上面的图片
   private boolean state=false;
   private int currentX;//获得位置
   boolean isTouching;//是否是触摸


    //有style资源文件时使用
   public TooggleButtonCustom(Context context, AttributeSet attrs, int defStyle) {
       super(context, attrs, defStyle);
       // TODO Auto-generated constructor stub
   }
    // xml布局文件中使用
   public TooggleButtonCustom(Context context, AttributeSet attrs) {
       super(context, attrs);
       // TODO Auto-generated constructor stub
   }
   //java代码中创建时使用这个构造方法
   public TooggleButtonCustom(Context context) {
       super(context);
       // TODO Auto-generated constructor stub
   }





   //设置背景图片
   public void setBackGroundPic(int switchBackground) {
       backBitmap = BitmapFactory.decodeResource(getResources(),switchBackground);


   }
   //设置前边图片
   public void setForePic(int slideButtonBackground) {
       foreBitmap = BitmapFactory.decodeResource(getResources(),slideButtonBackground);


   }
   //设置开关状态
   public void setState(boolean b) {
       this.state=b;

   }
   /**
   * 测量控件的宽高
   */
   @Override
   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
       super.onMeasure(widthMeasureSpec, heightMeasureSpec);
       setMeasuredDimension(backBitmap.getWidth(), backBitmap.getHeight());
   }

   /**
   * 绘制控件
   */
   @Override
   protected void onDraw(Canvas canvas) {
       // 1.平铺背景图片
       canvas.drawBitmap(backBitmap, 0, 0, null);

       if (isTouching) {
           int left = currentX - foreBitmap.getWidth()/2;
           //两个问题 ,位置不在中心,,移出范围

           if (left < 0) {
               left = 0;
           }else if (left > backBitmap.getWidth() - foreBitmap.getWidth()) {
               left = backBitmap.getWidth() - foreBitmap.getWidth();
           }

           canvas.drawBitmap(foreBitmap, left, 0, null);
       }else {
           // 2.根据状态去绘制上面图片
           if (state) {
               // 右边
               canvas.drawBitmap(foreBitmap,
                       backBitmap.getWidth() - foreBitmap.getWidth(), 0, null);
           } else {
               // 左边
               canvas.drawBitmap(foreBitmap, 0, 0, null);
           }
       }

   }

   /**
   * 触摸控件时调用的方法
   */
   @Override
   public boolean onTouchEvent(MotionEvent event) {
       switch (event.getAction()) {
       case MotionEvent.ACTION_DOWN:
           isTouching = true;
           currentX = (int) event.getX();
           break;
       case MotionEvent.ACTION_MOVE:
           isTouching = true;
           currentX = (int) event.getX();
           break;
       case MotionEvent.ACTION_UP:
           isTouching = false;
           currentX = (int) event.getX();

           state = currentX > backBitmap.getWidth()/2;
           break;

       default:
           break;
       }
       invalidate();//重复绘制控件自动调用OnDraw()
       return true;// 自己处理触摸事件
   }


}

//------------------------主布局文件---------------------------