surfaceView使用模板。

public class MySurferViewSImpleDraw extends SurfaceView implements SurfaceHolder.Callback,Runnable {
    private Canvas mCanvas;
    private Paint mPaint;
    private SurfaceHolder mHolder;
    private Boolean mIsDrawing=true;
    private Path mPath;

    private void init(){
        mPaint=new Paint();
        mPaint.setColor(Color.GRAY);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeWidth(30);
        //獲取holder
        mHolder=getHolder();
        //設置監聽
        mHolder.addCallback(this);
        mPath=new Path();
    }
    public MySurferViewSImpleDraw(Context context) {
        super(context);
        init();
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        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() {
            while(mIsDrawing){
                draw();
            }
    }

    void draw(){
        mCanvas=mHolder.lockCanvas();
        if (mCanvas==null)
            return;
        mCanvas.drawPath(mPath,mPaint);
        if (mCanvas!=null){
            mHolder.unlockCanvasAndPost(mCanvas);
        }
    }


    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int x,y;
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN:
                x= (int) event.getX();
                y= (int) event.getY();
                mPath.moveTo(x,y);
                break;
            case MotionEvent.ACTION_MOVE:
                x= (int) event.getX();
                y= (int) event.getY();
                mPath.lineTo(x,y);
                break;
        }

        return true;
    }
}