跑马灯控件 MarqueeView部分问题记录

跑马灯自定义控件 MarqueeView（https://github.com/sunfusheng/MarqueeView
） 继承自ViewFlipper。部分手机屏幕自动锁屏后立即按旁边的开机键，不用解锁就能回到页面，此时再调用startFlipping();不会再轮播。
原因是ViewFlipper监听了锁屏和解锁的广播，在锁屏时将mUserPresent这个属性设置为false,解锁之后重置为true, mUserPresent为true时才会轮播。部分手机由于不用解锁就回到了解锁状态，所以这个值就一直是false.

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (Intent.ACTION_SCREEN_OFF.equals(action)) {
                mUserPresent = false;
                updateRunning();
            } else if (Intent.ACTION_USER_PRESENT.equals(action)) {
                mUserPresent = true;
                updateRunning(false);
            }
        }
    };

//轮播的方法
private void updateRunning(boolean flipNow) {
        boolean running = mVisible && mStarted && mUserPresent;
        //mUserPresent为false则停止轮播
        if (running != mRunning) {
            if (running) {
                showOnly(mWhichChild, flipNow);
                postDelayed(mFlipRunnable, mFlipInterval);
            } else {
                removeCallbacks(mFlipRunnable);
            }
            mRunning = running;
        }
        if (LOGD) {
            Log.d(TAG, "updateRunning() mVisible=" + mVisible + ", mStarted=" + mStarted
                    + ", mUserPresent=" + mUserPresent + ", mRunning=" + mRunning);
        }
    }

解决方法：通过反射将mUserPresent设置为true

public void setUserPresent(boolean userPresent) {
        Class clazz = ViewFlipper.class;
        try {
            Field f = clazz.getDeclaredField("mUserPresent");
            f.setAccessible(true); //设置些属性是可以访问的
            f.setBoolean(this, userPresent);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
public boolean getUserPresent() {
        Class clazz = ViewFlipper.class;
        try {
            Field f = clazz.getDeclaredField("mUserPresent");
            f.setAccessible(true); //设置些属性是可以访问的
            return f.getBoolean(this);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        return false;
    }

屏幕解锁后判断mUserPresent是否为true，如果不是则设置其为true.