package com.pignet.surfaceviewdemo; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Path; import android.util.AttributeSet; import android.util.Log; import android.view.MotionEvent; import android.view.SurfaceHolder; import android.view.SurfaceView; /** * Created by DB on 2017/6/9. */ public class SurfaceViewTemplate extends SurfaceView implements SurfaceHolder.Callback,Runnable { private static final String TAG="SurfaceView"; //SurfaceHolder private SurfaceHolder mHolder; //用于绘图的Canvas private Canvas mCanvas; //子线程标志位 private boolean mIsDrawing; //画笔 private Paint mPaint; //路径 private Path mPath; public SurfaceViewTemplate(Context context) { super(context); initView(); } public SurfaceViewTemplate(Context context, AttributeSet attrs) { super(context, attrs); initView(); } public SurfaceViewTemplate(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initView(); } private void initView() { mHolder = getHolder(); //添加回调 mHolder.addCallback(this); mPath=new Path(); //初始化画笔 mPaint=new Paint(); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeWidth(6); mPaint.setAntiAlias(true); mPaint.setColor(Color.RED); setFocusable(true); setFocusableInTouchMode(true); this.setKeepScreenOn(true); } //Surface的生命周期 @Override public void surfaceCreated(SurfaceHolder holder) { mIsDrawing=true; new Thread(this).start(); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceDestroyed(SurfaceHolder holder) { mIsDrawing=false; } @Override public void run() { long start =System.currentTimeMillis(); while(mIsDrawing){ draw(); long end = System.currentTimeMillis(); if(end-start<100){ try{ Thread.sleep(100-end+start); } catch (InterruptedException e) { e.printStackTrace(); } } } } private void draw() { try{ //锁定画布并返回画布对象 mCanvas=mHolder.lockCanvas(); //接下去就是在画布上进行一下draw mCanvas.drawColor(Color.WHITE); mCanvas.drawPath(mPath,mPaint); }catch (Exception e){ }finally { //当画布内容不为空时，才post，避免出现黑屏的情况。 if(mCanvas!=null) mHolder.unlockCanvasAndPost(mCanvas); } } /** * 绘制触摸滑动路径 * @param event MotionEvent * @return true */ @Override public boolean onTouchEvent(MotionEvent event) { int x=(int) event.getX(); int y= (int) event.getY(); switch (event.getAction()){ case MotionEvent.ACTION_DOWN: Log.d(TAG, "onTouchEvent: down"); mPath.moveTo(x,y); break; case MotionEvent.ACTION_MOVE: Log.d(TAG, "onTouchEvent: move"); mPath.lineTo(x,y); break; case MotionEvent.ACTION_UP: Log.d(TAG, "onTouchEvent: up"); break; } return true; } /** * 清屏 * @return true */ public boolean reDraw(){ mPath.reset(); return true; } }
效果图：
四、tips：