Android自訂View—滑動開關

MainActivity如下:<喎?http://www.bkjia.com/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHByZSBjbGFzcz0="brush:java;">package cc.testview3;import cc.testview3.SwitchView.SwitchChangedListener;import android.os.Bundle;import android.widget.Toast;import android.app.Activity;/** * Demo描述: * 自訂View實現滑動開關 * * 測試裝置: * 解析度為480x854 */public class MainActivity extends Activity { private SwitchView mSwitchView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);init();} private void init(){ mSwitchView=(SwitchView) findViewById(R.id.switchView); mSwitchView.initSwitchStatus(true); mSwitchView.setOnSwitchChangedListener(new SwitchChangedListenerImpl()); } private class SwitchChangedListenerImpl implements SwitchChangedListener{@Overridepublic void OnChanged(boolean currentStatus) {Toast.makeText(MainActivity.this, "currentIsOff?-->"+currentStatus, Toast.LENGTH_SHORT).show();} }}

SwitchView如下:

package cc.testview3;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;public class SwitchView extends View  {private Bitmap mOnBitmap;private Bitmap mOffBitmap;private Bitmap mDotBitmap;private float currentX;private boolean currentIsSlipping=false;private boolean currentIsOff;private SwitchChangedListener mSwitchChangedListener;    private int dotWidth;    private int switchWidth;public SwitchView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);initSwitchView();}public SwitchView(Context context, AttributeSet attrs) {super(context, attrs);initSwitchView();}public SwitchView(Context context) {super(context);initSwitchView();}private void initSwitchView(){mOnBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.on);mOffBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.off);mDotBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.dot);dotWidth=mDotBitmap.getWidth();switchWidth=mOnBitmap.getWidth();this.setOnTouchListener(new TouchListenerImpl());}public void initSwitchStatus(boolean isOff){if (isOff) {currentX=switchWidth;} else {currentX=0;}currentIsOff=isOff;}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);}@Overrideprotected void onLayout(boolean changed, int left, int top, int right,int bottom) {super.onLayout(changed, left, top, right, bottom);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);Matrix matrix=new Matrix();Paint paint=new Paint();//先畫出開關的背景(關/開)if (currentIsOff) {canvas.drawBitmap(mOffBitmap, matrix, paint);} else {canvas.drawBitmap(mOnBitmap, matrix, paint);}//再畫出滑塊//1 在滑動中(if),滑塊的left就是不斷變化的currentX//2 手指抬起後(else)停止滑動時.此時的開關應該在左右//  其中一側處於開或者關的狀態if (currentIsSlipping) {canvas.drawBitmap(mDotBitmap, currentX, 17, paint);} else {if (currentIsOff) {canvas.drawBitmap(mDotBitmap, currentX-dotWidth, 17, paint); }else{canvas.drawBitmap(mDotBitmap, currentX, 17, paint); }}}private class TouchListenerImpl implements OnTouchListener{@Overridepublic boolean onTouch(View v, MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_DOWN:break;case MotionEvent.ACTION_MOVE:currentIsSlipping=true;currentX = event.getX();if (currentX>switchWidth/2) {currentIsOff=true;}else {currentIsOff=false;}//防止向右邊滑動時越界if (event.getX()>switchWidth-dotWidth) {currentX = switchWidth-dotWidth;currentIsOff=true;}//防止向左邊滑動時越界if (event.getX()<0) {currentX=0;currentIsOff=false;}//重繪!!!invalidate();break;case MotionEvent.ACTION_UP:currentIsSlipping=false;currentX = event.getX();//抬起時若(if)已經超過開關一般的長度,則讓其處於關閉的狀態//否則(else)讓其處於開啟的狀態if (currentX >= switchWidth / 2) {currentX = switchWidth;currentIsOff=true;} else {currentX = 0;currentIsOff=false;}if (mSwitchChangedListener != null) {mSwitchChangedListener.OnChanged(currentIsOff);}// 重繪!!!invalidate();break;default:break;}return true;}}// 介面public interface SwitchChangedListener {public void OnChanged(boolean currentIsOff);}public void setOnSwitchChangedListener(SwitchChangedListener switchChangedListener) {this.mSwitchChangedListener = switchChangedListener;}}

main.xml如下: