Android自定义SurfaceView实现画板功能

/**
 * 2016年7月26日17:20:13
 * @author 小瓶盖 blog 
 *
 */
public class SecondSurfaceView extends SurfaceView implements SurfaceHolder.Callback,Runnable{

 /**
 * 是否处于绘制状态
 */
 private boolean mIsDrawing;
 /**
 * 帮助类
 */
 private SurfaceHolder mHolder;
 /**
 * 画布
 */
 private Canvas mCanvas;
 /**
 * 路径
 */
 private Path mPath;
 /**
 * 画笔
 */
 private Paint mPaint;

 public SecondSurfaceView(Context context, AttributeSet attrs, int defStyle) {
 super(context, attrs, defStyle);
 initView();
 }

 public SecondSurfaceView(Context context, AttributeSet attrs) {
 super(context, attrs);
 initView();
 }

 public SecondSurfaceView(Context context) {
 super(context);
 initView();
 }
 @Override
 public boolean onTouchEvent(MotionEvent event) {

 int x=(int) event.getX();
 int y=(int) event.getY();
 switch (event.getAction()) {
 case MotionEvent.ACTION_DOWN:
  mPath.moveTo(x, y);
  break;
 case MotionEvent.ACTION_MOVE:
  mPath.lineTo(x, y);
  break;
 case MotionEvent.ACTION_UP:

  break;
 default:
  break;
 }

 return true;
 }

 private void initView() {
 mHolder=getHolder();
 mHolder.addCallback(this);
 setFocusable(true);
 setFocusableInTouchMode(true);
 this.setKeepScreenOn(true);

 mPath=new Path();

 mPaint=new Paint();
 mPaint.setAntiAlias(true);
 mPaint.setColor(Color.BLACK);
 mPaint.setStyle(Style.STROKE);
 mPaint.setStrokeWidth(15);
 }

 @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 (Exception e) {
  e.printStackTrace();
  }
 }
 }

 @Override
 public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {


 }

 @Override
 public void surfaceCreated(SurfaceHolder arg0) {
 mIsDrawing=true;
 new Thread(this).start();
 }

 @Override
 public void surfaceDestroyed(SurfaceHolder arg0) {
 mIsDrawing=false;

 }
 private void draw(){
 try {
  mCanvas=mHolder.lockCanvas();
  mCanvas.drawColor(Color.WHITE);
  mCanvas.drawPath(mPath, mPaint);
 } catch (Exception e) {
  e.printStackTrace();
 }finally{
  if (mCanvas!=null) {
  mHolder.unlockCanvasAndPost(mCanvas);
  }
 }
 }
 /**
 * 清除内容
 */
 public void clean(){
 initView();
 }
}

/**
 * 2016年7月26日17:20:13
 * @author 小瓶盖 blog *
 */
public class MainActivity extends Activity{
 SecondSurfaceView surfaceView;

 @Override
 protected void onCreate(Bundle savedInstanceState) {

 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);

 surfaceView=(SecondSurfaceView)findViewById(R.id.surfaceview);
 }

 public void onClick(View v){
 surfaceView.clean();
 }

}