问自定义视图动画比自定义SurfaceView动画更平滑？

EN

public class TimerView extends View {

    private Paint mPiePaint;
    private RectF mShadowBounds;
    private float diameter;

    int startCount = 0;
    private PanelThread thread;

    public TimerView(Context context) {
        super(context);
        init();
    }

    public TimerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public TimerView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    @TargetApi(VERSION_CODES.LOLLIPOP)
    public TimerView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init();
    }

    private void init() {
        mPiePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPiePaint.setStyle(Paint.Style.FILL);
        mPiePaint.setColor(0xff000000);

    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        // Account for padding
        float xpad = (float)(getPaddingLeft() + getPaddingRight());
        float ypad = (float)(getPaddingTop() + getPaddingBottom());

        float ww = (float)w - xpad;
        float hh = (float)h - ypad;

        // Figure out how big we can make the pie.
        diameter = Math.min(ww, hh);
        mShadowBounds = new RectF(0, 0, diameter, diameter);

    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (startCount == 360) startCount= 0;
        canvas.drawArc(mShadowBounds,
                0, startCount, true, mPiePaint);
        invalidate();
        startCount++;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int minw = getPaddingLeft() + getPaddingRight() + getSuggestedMinimumWidth();
        int w = resolveSizeAndState(minw, widthMeasureSpec, 1);
        int h = resolveSizeAndState(MeasureSpec.getSize(w), heightMeasureSpec, 0);
        setMeasuredDimension(w, h);
    }

}

public class TimerSurfaceView extends SurfaceView implements SurfaceHolder.Callback {

    private Paint mPiePaint;
    private RectF mShadowBounds;
    private float diameter;

    int startCount = 0;
    private PanelThread thread;

    public TimerSurfaceView(Context context) {
        super(context);
        init();
    }

    public TimerSurfaceView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public TimerSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    @TargetApi(VERSION_CODES.LOLLIPOP)
    public TimerSurfaceView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init();
    }

    private void init() {
        getHolder().addCallback(this);
        mPiePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPiePaint.setStyle(Paint.Style.FILL);
        mPiePaint.setColor(0xff000000);

    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        // Account for padding
        float xpad = (float)(getPaddingLeft() + getPaddingRight());
        float ypad = (float)(getPaddingTop() + getPaddingBottom());

        float ww = (float)w - xpad;
        float hh = (float)h - ypad;

        // Figure out how big we can make the pie.
        diameter = Math.min(ww, hh);
        mShadowBounds = new RectF(0, 0, diameter, diameter);

    }

    protected void drawSomething(Canvas canvas) {
        canvas.drawColor(0xFFEEEEEE);

        if (startCount == 360) startCount= 0;
        canvas.drawArc(mShadowBounds,
                0, startCount, true, mPiePaint);
        startCount++;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int minw = getPaddingLeft() + getPaddingRight() + getSuggestedMinimumWidth();
        int w = resolveSizeAndState(minw, widthMeasureSpec, 1);
        int h = resolveSizeAndState(MeasureSpec.getSize(w), heightMeasureSpec, 0);
        setMeasuredDimension(w, h);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        setWillNotDraw(false); //Allows us to use invalidate() to call onDraw()
        thread = new PanelThread(getHolder(), this); //Start the thread that
        thread.setRunning(true);                     //will make calls to
        thread.start();                              //onDraw()
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // tell the thread to shut down and wait for it to finish
        // this is a clean shutdown
        boolean retry = true;
        while (retry) {
            try {
                thread.join();
                retry = false;
            } catch (InterruptedException e) {
                // try again shutting down the thread
            }
        }
    }
}

class PanelThread extends Thread {
    private SurfaceHolder surfaceHolder;
    private TimerSurfaceView panel;
    private boolean starRunning = false;


    public PanelThread(SurfaceHolder surfaceHolder, TimerSurfaceView panel) {
        this.surfaceHolder = surfaceHolder;
        this.panel = panel;
    }


    public void setRunning(boolean run) { //Allow us to stop the thread
        starRunning = run;
    }


    @Override
    public void run() {
        Canvas c;
        while (starRunning) {     //When setRunning(false) occurs, starRunning is
            c = null;      //set to false and loop ends, stopping thread
            try {
                c = surfaceHolder.lockCanvas(null);
                synchronized (surfaceHolder) {
                    //Insert methods to modify positions of items in onDraw()
                    panel.drawSomething(c);
                }
            } finally {
                if (c != null) {
                    surfaceHolder.unlockCanvasAndPost(c);
                }
            }
        }
    }
}