[问题]为什么我的Handler的handleMessage次数变少了？

来源：互联网发布：python 安装websocket 编辑：程序博客网时间：2024/04/29 16:41

public Handler mHandler = new Handler() {        @Override        public void handleMessage(Message msg) {            switch (msg.what) {                // Upon receiving the update pulse, we have the view perform a                // update and then enqueue a new message to pulse at the desired                // next time.                case UPDATE_MSG: {                    update();                    if (mUpdateFlag == false) {                        LogUtils.d(("end  update 2"));                        stopUpdating();                    } else {                        LogUtils.d("msg");                        mHandler.sendMessageDelayed(mHandler.obtainMessage(UPDATE_MSG), UPDATE_DELAY);                    }                    break;                }                default:                    super.handleMessage(msg);            }        }    };

    /**     * Start up the pulse to update the screen, clearing any existing pulse to     * ensure that we don't have multiple pulses running at a time.     */    void startUpdating() {        LogUtils.d("start");        mStartFlag = true;        mUpdateFlag = true;        mHandler.removeMessages(UPDATE_MSG);        mHandler.sendMessageDelayed(mHandler.obtainMessage(UPDATE_MSG), UPDATE_DELAY);    }    /**     * Stop the pulse to fade the screen.     */    void stopUpdating() {        LogUtils.d("stop");        mHandler.removeMessages(UPDATE_MSG);    }

public synchronized void update() {        LogUtils.d("update 1 " + System.currentTimeMillis());        if (mCanvas != null) {            LogUtils.d("update 2 " + System.currentTimeMillis());            int left = mRect.left;            int top = mRect.top;            int right = mRect.right;            int bottom = mRect.bottom;            if (left < 0)                left = 0;            if (top < 0)                top = 0;            if (right < 0)                right = 0;            if (bottom < 0)                bottom = 0;            if (mNewRegionFlag == true) {                if (mEvent == 1) {                    LogUtils.d(TAG, ("end  update 1\n"));                    mUpdateFlag = false;                }            } else {                LogUtils.d(TAG, ("left=" + left + " top=" + top + " right=" + right + " bottom=" + bottom + ""));                mCanvas.drawPath(mPath, mPaint); //绘制path                if (mUpdateType == 0)                    if (Constants.TEST)                        invalidate(left, top, right, bottom, UPDATE_MODE_PARTIAL);                    else                        invalidate(left, top, right, bottom);                else                    invalidate(left, top, right, bottom);                mNewRegionFlag = true;            }        }    }

onTouchEventswitch (event.getAction()) {                case MotionEvent.ACTION_DOWN:                    LogUtils.d(TAG, ("touch down\n"));                    startUpdating();                breadk;                case MotionEvent.ACTION_UP:                LogUtils.d(TAG, ("touch up\n"));                 mUpdateFlag = false;                break;

测试都是以画一个圈来测试log次数

现在是这样操作的，进来初始化该View，直接画线，结果打印如下

然后，我在此activity的基础上新建了一个空白的（清空画布，设置画布）

日志差不多少了一半，（测试多次）

但是总时间是一样的，误差不过50ms，中间的次数变少了，所以才有后者实时速度跟不上前者，update的脉冲没有实时跟上（类似游戏掉帧）。

不知道是什么原因导致的，是不是Handler机制

欢迎留言。。。。。。讨论

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