android自定义滑动开关控件，适合所有的android系统

我们都知道Android4.0以上才带有滑动开关Switch，那么在4.0以下呢，很多人会选择用CheckBox，放两张图片，但是这样子只能点击，效果不太好，所以我就自定义了滑动开关WiperSwitch这么一个控件，下面先把截图贴上吧，这蹩脚的图片真戳啊，大家可以自己换三张图片



[java] view
plaincopy





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);

}

}

用法是，先定义XML文件

[html] view
plaincopy





<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>

新建一个Activity

[java] view
plaincopy





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);

}

}

代码全部上完了，写的不好的地方欢迎大牛指点！

哦，忘记了还有三张蹩脚的图片没传