android自訂滑動開關控制項，適合所有的android系統

我們都知道Android4.0以上才帶有滑動開關Switch，那麼在4.0以下呢，很多人會選擇用CheckBox，放兩張圖片，但是這樣子只能點擊，效果不太好，所以我就自訂了滑動開關WiperSwitch這麼一個控制項，下面先把貼上吧，這蹩腳的圖片真戳啊，大家可以自己換三張圖片

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;/** * 按下時的x和當前的x */private float downX, nowX;/** * 記錄使用者是否在滑動 */private boolean onSlip = false;/** * 當前的狀態 */private boolean nowStatus = false;/** * 監聽介面 */private OnChangedListener listener;public WiperSwitch(Context context) {super(context);init();}public WiperSwitch(Context context, AttributeSet attrs) {super(context, attrs);init();}public void init(){//載入圖片資源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;//根據nowX設定背景，開或者關狀態if (nowX < (bg_on.getWidth()/2)){canvas.drawBitmap(bg_off, matrix, paint);//畫出關閉時的背景}else{canvas.drawBitmap(bg_on, matrix, paint);//畫出開啟時的背景 }if (onSlip) {//是否是在滑動狀態,  if(nowX >= bg_on.getWidth())//是否划出指定範圍,不能讓滑塊跑到外頭,必須做這個判斷x = bg_on.getWidth() - slipper_btn.getWidth()/2;//減去滑塊1/2的長度elsex = nowX - slipper_btn.getWidth()/2;}else {if(nowStatus){//根據當前的狀態設定滑塊的x值x = bg_on.getWidth() - slipper_btn.getWidth();}else{x = 0;}}//對滑塊滑動進行異常處理，不能讓滑塊出界if (x < 0 ){x = 0;}else if(x > bg_on.getWidth() - slipper_btn.getWidth()){x = bg_on.getWidth() - slipper_btn.getWidth();}//畫出滑塊canvas.drawBitmap(slipper_btn, x , 0, paint); }@Overridepublic 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;}}//重新整理介面invalidate();return true;}/** * 為WiperSwitch設定一個監聽，供外部調用的方法 * @param listener */public void setOnChangedListener(OnChangedListener listener){this.listener = listener;}/** * 設定滑動開關的初始狀態，供外部調用 * @param checked */public void setChecked(boolean checked){if(checked){nowX = bg_off.getWidth();}else{nowX = 0;}nowStatus = checked;}    /**     * 回調介面     * @author len     *     */public interface OnChangedListener {public void OnChanged(WiperSwitch wiperSwitch, boolean checkState);}}

用法是，先定義XML檔案

<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>

建立一個Activity

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 {@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);//執行個體化WiperSwitchWiperSwitch wiperSwitch = (WiperSwitch)findViewById(R.id.wiperSwitch1);//設定初始狀態為falsewiperSwitch.setChecked(false);//設定監聽wiperSwitch.setOnChangedListener(this);}@Overridepublic void OnChanged(WiperSwitch wiperSwitch, boolean checkState) {Log.e("log", "" + checkState);}}

代碼全部上完了，寫的不好的地方歡迎大牛指點！

哦，忘記了還有三張蹩腳的圖片沒傳