android自定义滑动开关组件

package com.example.wiperswitch;



import android.content.Context;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.Matrix;

import android.graphics.Paint;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.View;

import android.view.View.OnTouchListener;



/**

 * 

 * @author xiaanming

 *

 */

public class WiperSwitch extends View implements OnTouchListener{

    private Bitmap bg_on, bg_off, slipper_btn;

    /**

     * 按下时的x和当前的x

     */

    private float downX, nowX;

    

    /**

     * 记录用户是否在滑动

     */

    private boolean onSlip = false;

    

    /**

     * 当前的状态

     */

    private boolean nowStatus = false;

    

    /**

     * 监听接口

     */

    private OnChangedListener listener;

    

    

    public WiperSwitch(Context context) {

        super(context);

        init();

    }



    public WiperSwitch(Context context, AttributeSet attrs) {

        super(context, attrs);

        init();

    }

    

    public void init(){

        //载入图片资源

        bg_on = BitmapFactory.decodeResource(getResources(), R.drawable.on_btn);

        bg_off = BitmapFactory.decodeResource(getResources(), R.drawable.off_btn);

        slipper_btn = BitmapFactory.decodeResource(getResources(), R.drawable.white_btn);

        

        setOnTouchListener(this);

    }

    

    protected void onDraw(Canvas canvas) {

        super.onDraw(canvas);

        Matrix matrix = new Matrix();

        Paint paint = new Paint();

        float x = 0;

        

        //根据nowX设置背景，开或者关状态

        if (nowX < (bg_on.getWidth()/2)){

            canvas.drawBitmap(bg_off, matrix, paint);//画出关闭时的背景

        }else{

            canvas.drawBitmap(bg_on, matrix, paint);//画出打开时的背景 

        }

        

        if (onSlip) {//是否是在滑动状态,  

            if(nowX >= bg_on.getWidth())//是否划出指定范围,不能让滑块跑到外头,必须做这个判断

                x = bg_on.getWidth() - slipper_btn.getWidth()/2;//减去滑块1/2的长度

            else

                x = nowX - slipper_btn.getWidth()/2;

        }else {

            if(nowStatus){//根据当前的状态设置滑块的x值

                x = bg_on.getWidth() - slipper_btn.getWidth();

            }else{

                x = 0;

            }

        }

        

        //对滑块滑动进行异常处理，不能让滑块出界

        if (x < 0 ){

            x = 0;

        }

        else if(x > bg_on.getWidth() - slipper_btn.getWidth()){

            x = bg_on.getWidth() - slipper_btn.getWidth();

        }

        

        //画出滑块

        canvas.drawBitmap(slipper_btn, x , 0, paint); 

    }



    @Override

    public boolean onTouch(View v, MotionEvent event) {

        switch(event.getAction()){

        case MotionEvent.ACTION_DOWN:{

            if (event.getX() > bg_off.getWidth() || event.getY() > bg_off.getHeight()){

                return false;

            }else{

                onSlip = true;

                downX = event.getX();

                nowX = downX;

            }

            break;

        }

        case MotionEvent.ACTION_MOVE:{

            nowX = event.getX();

            break;

        }

        case MotionEvent.ACTION_UP:{

            onSlip = false;

            if(event.getX() >= (bg_on.getWidth()/2)){

                nowStatus = true;

                nowX = bg_on.getWidth() - slipper_btn.getWidth();

            }else{

                nowStatus = false;

                nowX = 0;

            }

            

            if(listener != null){

                listener.OnChanged(WiperSwitch.this, nowStatus);

            }

            break;

        }

        }

        //刷新界面

        invalidate();

        return true;

    }

    

    

    

    /**

     * 为WiperSwitch设置一个监听，供外部调用的方法

     * @param listener

     */

    public void setOnChangedListener(OnChangedListener listener){

        this.listener = listener;

    }

    

    

    /**

     * 设置滑动开关的初始状态，供外部调用

     * @param checked

     */

    public void setChecked(boolean checked){

        if(checked){

            nowX = bg_off.getWidth();

        }else{

            nowX = 0;

        }

        nowStatus = checked;

    }



    

    /**

     * 回调接口

     * @author len

     *

     */

    public interface OnChangedListener {

        public void OnChanged(WiperSwitch wiperSwitch, boolean checkState);

    }





}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent" >



    <com.example.wiperswitch.WiperSwitch

        android:id="@+id/wiperSwitch1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" />





</RelativeLayout>

package com.example.wiperswitch;





import android.app.Activity;

import android.os.Bundle;

import android.util.Log;



import com.example.wiperswitch.WiperSwitch.OnChangedListener;



public class MainActivity extends Activity implements OnChangedListener {



    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        //实例化WiperSwitch

        WiperSwitch wiperSwitch = (WiperSwitch)findViewById(R.id.wiperSwitch1);

        

        //设置初始状态为false

        wiperSwitch.setChecked(false);

        

        //设置监听

        wiperSwitch.setOnChangedListener(this);

    }





    @Override

    public void OnChanged(WiperSwitch wiperSwitch, boolean checkState) {

        Log.e("log", "" + checkState);

    }





}

代码中，有一个回调的写法，自定义组件中挺常用的，大家可以借鉴一下！

转自：http://blog.csdn.net/xiaanming/article/details/8842453