本文实例介绍了Android如何画出触摸轨迹的方法，分享给大家供大家参考，具体内容如下

效果图：

实现代码：

package com.android.gameview5;import android.app.Activity;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.os.Bundle;import android.view.MotionEvent;import android.view.SurfaceHolder;import android.view.SurfaceHolder.Callback;import android.view.SurfaceView;import android.view.Window;import android.view.WindowManager;public class SurfaceViewActivity3 extends Activity { public void onCreate(Bundle s){ super.onCreate(s); //全屏显示 requestWindowFeature(Window.FEATURE_NO_TITLE); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(new MyView(this)); } public class MyView extends SurfaceView implements Callback,Runnable{ public static final int TIME_IN_FRAME =50; Paint mPaint = null; Paint mTextPaint = null; SurfaceHolder mSurfaceHolder = null; boolean mRunning = false; Canvas mCanvas = null; private Path mPath; private float mPosX,mPosY; public MyView(Context context){super(context);this.setFocusable(true);this.setFocusableInTouchMode(true); mSurfaceHolder = this.getHolder(); mSurfaceHolder.addCallback(this); mCanvas = new Canvas(); mPaint = new Paint(); mPaint.setColor(Color.BLACK); mPaint.setAntiAlias(true); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeCap(Paint.Cap.ROUND); mPaint.setStrokeWidth(6); mPath = new Path(); mTextPaint = new Paint(); mTextPaint.setColor(Color.BLACK); mTextPaint.setTextSize(15); }public boolean onTouchEvent(MotionEvent event){ int action = event.getAction(); float x = event.getX(); float y = event.getY(); switch(action){ case MotionEvent.ACTION_DOWN: mPath.moveTo(x, y); break; case MotionEvent.ACTION_MOVE: mPath.quadTo(mPosX, mPosY, x, y); break; case MotionEvent.ACTION_UP: //mPath.reset(); break; } //记录当前触摸点得当前得坐标 mPosX = x; mPosY = y;return true;}private void onDraw(){mCanvas.drawColor(Color.WHITE);//绘制曲线mCanvas.drawPath(mPath, mPaint);mCanvas.drawText("当前触笔X："+mPosX,0,20,mTextPaint);mCanvas.drawText("当前触笔Y:"+mPosY,0,40,mTextPaint);}public void run() {// TODO Auto-generated method stubwhile(mRunning){long startTime = System.currentTimeMillis();synchronized(mSurfaceHolder){mCanvas = mSurfaceHolder.lockCanvas();onDraw();mSurfaceHolder.unlockCanvasAndPost(mCanvas);}long endTime = System.currentTimeMillis();int diffTime = (int) (endTime - startTime);while(diffTime<=TIME_IN_FRAME){diffTime =(int)(System.currentTimeMillis()-startTime);Thread.yield();}}}@Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height) {// TODO Auto-generated method stub}@Overridepublic void surfaceCreated(SurfaceHolder holder) {mRunning = true;new Thread(this).start();}@Overridepublic void surfaceDestroyed(SurfaceHolder holder) {// TODO Auto-generated method stubmRunning = false;} }}

以上就是Android轻松画出触摸轨迹的具体方法，希望对大家的学习有所帮助。