switchbutton

mainactivity--------------------------

package com.liulailin.day03_myswitchbutton;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        MyButton myButton = (MyButton) findViewById(R.id.myButton);
        myButton.setState(false);
        myButton.setBackgroudColor(R.mipmap.switch_background);
        myButton.setSlidingColor(R.mipmap.slide_button_background);


        myButton.setOnButtonStateChangedListener(new OnButtonStateChangedListener() {
            @Override
            public void onButtonState(boolean state) {
                if (state){
                    Toast.makeText(MainActivity.this, "开关是开的", Toast.LENGTH_SHORT).show();
                }else{
                    Toast.makeText(MainActivity.this, "开关是关的状态", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

mybutton-----------------------------------

package com.liulailin.day03_myswitchbutton;

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

import static android.R.attr.left;

/**
 * Created by Administrator on 2018/3/9.
 */

public class MyButton extends View {

    boolean state = false;
    Bitmap buttonBackGround;
    Bitmap buttonSlidingBack;
    private boolean isSliding;
    private int currentx;

    OnButtonStateChangedListener MyListener;


    public MyButton(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        //设置背景图片的宽和高
        setMeasuredDimension(buttonBackGround.getWidth(),buttonBackGround.getHeight());




    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //1:绘制背景图片
        canvas.drawBitmap(buttonBackGround,0,0,null);
        //2：绘制滑动块的图片，并指定其位置

        //判断是否正在滑动中，如果在滑动中
        //需要根据手指按下的x轴的值，来去绘制滑动left位置
        int onLeft = buttonBackGround.getWidth()-buttonSlidingBack.getWidth();
        if (isSliding){
            //左右边界超出   就是按下不在中心的位置
            int left = currentx-buttonSlidingBack.getWidth()/2;
            if (left<0){
                left=0;
            }else if(left>onLeft){
                left=onLeft;
            }


            //当前手指按下的不是滑动块的中心点


            //正在滑动中我们应该走这
            canvas.drawBitmap(buttonSlidingBack,left,0,null);

        }else {
            //不是正在滑动中我们是不是要有一个状态
            if (state){
                //开的状态

                canvas.drawBitmap(buttonSlidingBack,onLeft,0,null);
            }else {
                //关的状态
                canvas.drawBitmap(buttonSlidingBack,0,0,null);
            }
        }


    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:

                isSliding = true;
                currentx = (int) event.getX();

                break;
            case MotionEvent.ACTION_MOVE:
                currentx = (int) event.getX();
                break;
            case MotionEvent.ACTION_UP:
               isSliding = false;
                currentx = (int) event.getX();
               boolean flag =  currentx>buttonBackGround.getWidth()/2;


                       if(flag!=state && MyListener!=null){
                           MyListener.onButtonState(flag);
                       }

                if (currentx<buttonBackGround.getWidth()/2){
                    //当前x 轴的值，<背景图片的一半，进入关的状态

                    state=false;

                }else {
                     //如果当前x轴的值，>背景图片的一半，进入开的状态
                    state=true;
                }


                //调用用户的回调事件



                break;
        }

        //让其重新绘制的方法
        invalidate();
        return true;
    }

    //设置按钮的开关的状态
    public void setState(boolean b) {
        state = b;
    }

    //设置按钮的背景颜色
    public void setBackgroudColor(int backGround) {

     buttonBackGround = BitmapFactory.decodeResource(getResources(), backGround);

    }

    //设置滑动块的
    public void setSlidingColor(int slidingBack) {
        buttonSlidingBack = BitmapFactory.decodeResource(getResources(), slidingBack);
    }


    public void setOnButtonStateChangedListener(OnButtonStateChangedListener listener){
        MyListener =listener;
    }
}

onbuttonstatechangelistener

package com.liulailin.day03_myswitchbutton;

/**
 * Created by Administrator on 2018/3/10.
 * 开关状态的监听事件
 */

public interface OnButtonStateChangedListener {

    public  void onButtonState(boolean state);
}