android.os.Handler#removeCallbacksAndMessages ( )源码实例Demo

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setStyle(android.support.v4.app.DialogFragment.STYLE_NO_TITLE, R.style.AppTheme_AppCompat_Dialog_Alert);
    mHandler = new Handler(Looper.getMainLooper()) {
        @Override
        public void handleMessage(Message msg) {
            mProgress.setProgress(progress++);
            if (mProgress.getProgress() == 100) {
                mHandler.removeCallbacksAndMessages(null);
            } else {
                mHandler.sendEmptyMessageDelayed(1, 100);
            }
            super.handleMessage(msg);
        }
    };
    if (savedInstanceState != null) {
        progress = savedInstanceState.getInt("PROGRESS");
    }

}
 

public TextViewLinkHandler(ClickableText clickableText, String subreddit, Spannable sequence) {
    this.clickableText = clickableText;
    this.subreddit = subreddit;
    this.sequence = sequence;

    clickHandled = false;
    handler = new Handler();
    longClicked = new Runnable() {
        @Override
        public void run() {
            // long click
            clickHandled = true;

            handler.removeCallbacksAndMessages(null);
            if (link != null && link.length > 0 && link[0] != null) {
                TextViewLinkHandler.this.clickableText.onLinkLongClick(link[0].getURL(), event);
            }

        }
    };
}
 

public void startFalling() {
    stopped = false;
    Handler handler = getHandler();
    if (handler != null) {
        handler.removeCallbacksAndMessages(runnable);
    }
    post(runnable);
}
 

public void stopFalling() {
    stopped = true;
    Handler handler = getHandler();
    if (handler != null) {
        handler.removeCallbacksAndMessages(runnable);
    }
}
 

@Override
public void start(long position) {
    Handler handler = this.handler;
    if (handler == null) {
        prepare();
        handler = this.handler;
    } else {
        handler.removeCallbacksAndMessages(null);
    }
    if (handler != null) {
        handler.obtainMessage(DrawHandler.START, position).sendToTarget();
    }
}
 

public void startOrStopConnectionTester() {
    if (mConnectionTester == null) {
        // start the range tester
        sendBtCommand("R*I0000"); // turn rssi monitoring off
        mConnectionTester = new ConnectionTester();

        mConnectionTesterSendHandler = new Handler() {
            public void handleMessage(Message msg) {
                AppState app = AppState.getInstance();
                if (app.isConnected && app.raceState != null && !app.raceState.isStarted && app.mConnectionTester != null) {
                    AppState.getInstance().sendBtCommand("%" + String.format("%04X", mConnectionTester.getNextValueToSend()));
                    mConnectionTester.calcDiffTimes();
                    emitEvent(DataAction.ConnectionTester);
                }
                sendEmptyMessageDelayed(0, mConnectionTester.SEND_DELAY_MS);
            }
        };
        mConnectionTesterSendHandler.sendEmptyMessage(0);
    }
    else {
        // stop the range tester
        mConnectionTesterSendHandler.removeCallbacksAndMessages(null);
        mConnectionTesterSendHandler = null;
        mConnectionTester = null;
        sendBtCommand("R*I0064"); // turn rssi monitoring off
    }
}
 

private void stopAnimAndRemoveCallbacks(){
    isStart=false;
    for (Map.Entry<String, ValueAnimator> entry : animMap.entrySet()) {
        entry.getValue().end();
    }
    Handler handler=this.getHandler();
    if (handler!=null){
        handler.removeCallbacksAndMessages(null);
    }
}
 

private void updateAutoScroll() {
    Handler handler = getAutoScrollHandler();
    handler.removeCallbacksAndMessages(null);
    if (mIsAutoScrollEnabled && mAutoScrollIntervalInMilliseconds > 0
            && getItemCount() > 1 && getLayoutManager() != null) {
        handler.postDelayed(this, mAutoScrollIntervalInMilliseconds);
    }
}
 

@Override
public void run() {
    Handler handler = getAutoScrollHandler();

    ViewPagerLayoutManager layoutManager = getLayoutManager();
    if (layoutManager == null) {
        handler.removeCallbacksAndMessages(null);
        return;
    }
    layoutManager.smoothScrollToNextPosition();
    handler.postDelayed(this, mAutoScrollIntervalInMilliseconds);
}
 

/**
 * 停止进度
 */
public void stop() {
    mState = STATE_PREPARE;
    invalidate();
    Handler handler = getHandler();
    if (handler != null) {
        handler.removeCallbacksAndMessages(null);
    }
}
 

@Override
public void reset() {
    checkIsNotReleased();

    if (!mState.canCallReset()) {
        return;
    }

    if (mPlayer != null) {
        mPlayer.reset();
    }

    if (mHandler != null) {
        mHandler.removeCallbacksAndMessages(null);
    }

    // Clear all messages to avoid unexpected error callback
    Handler superEventHandler = (mSuperEventHandler != null) ? mSuperEventHandler.get() : null;
    if (superEventHandler != null) {
        superEventHandler.removeCallbacksAndMessages(null);
    }

    mIsLooping = false;
    mSeekPosition = SEEK_POS_NOSET;
    mPendingSeekPosition = SEEK_POS_NOSET;
    mDuration = 0;

    mState.transitToIdleState();
}
 

public void close() {
    Handler handler = mAsyncHandler;
    mAsyncHandler = null;
    if (handler != null) {
        handler.removeCallbacksAndMessages(null);
    }
    if (mHandlerThread != null) {
        mHandlerThread.quit();
        mHandlerThread = null;
    }
}
 

public void blinkEmissionView(final int position) {
    Handler handler;
    switch (position) {
        case 0:
            handler = startHandler;
            break;
        case 1:
            handler = endHandler;
            break;
        case 2:
            handler = cancelHandler;
            break;
        case 3:
            handler = repeatHandler;
            break;
        case 4:
            handler = pauseHandler;
            break;
        case 5:
            handler = resumeHandler;
            break;
        default:
            handler = updateHandler;
            break;
    }
    if (emissionViews[position].isSelected()) {
        handler.removeCallbacksAndMessages(null);
        emissionViews[position].setSelected(false);
    } else {
        emissionViews[position].setSelected(true);
        handler.removeCallbacksAndMessages(null);
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                if (emissionViews != null && emissionViews[position] != null) {
                    emissionViews[position].setSelected(false);
                }
            }
        }, BLINK_DURATION);
    }
}