锁屏时间格式不随多用户的时间格式变化而变化？

背景：时间格式有12//24小时制，系统设置时间格式之后，状态栏和锁屏的时间显示也会相应的发生变化，但是现在发现一个问题：当我切换到多用户设置时间格式的时候发现，状态栏的时间格式变化正常，但是锁屏时间格式，只会随着主用户的时间格式进行变化。基于这个现象，我就去朝看锁屏时间格式设置的相关流程代码。

使用的时间格式，有个对应的字段值进行存储，存储在Settings.System.TIME_12_24字段里，如果锁屏需要刷新时间格式，大概会监听这个字段，所以我根据这个字段查看锁屏相关代码对它的监听。
1.frameworks/base/packages/SystemUI/src/com/android/keyguard/KeyguardUpdateMonitor.java

       mTimeFormatChangeObserver = new ContentObserver(mHandler) {
            @Override
            public void onChange(boolean selfChange) {
                mHandler.sendMessage(mHandler.obtainMessage(
                        MSG_TIME_FORMAT_UPDATE,
                        Settings.System.getString(
                                mContext.getContentResolver(),
                                Settings.System.TIME_12_24)));
            }
        };
        mContext.getContentResolver().registerContentObserver(
                Settings.System.getUriFor(Settings.System.TIME_12_24),
                false, mTimeFormatChangeObserver, UserHandle.USER_ALL);

根据MSG_TIME_FORMAT_UPDATE，查看到：

    /**
     * Handle (@line #MSG_TIME_FORMAT_UPDATE}
     *
     * @param timeFormat "12" for 12-hour format, "24" for 24-hour format
     */
    private void handleTimeFormatUpdate(String timeFormat) {
        Assert.isMainThread();
        if (DEBUG || true) Log.d(TAG, "handleTimeFormatUpdate timeFormat=" + timeFormat);
        for (int i = 0; i < mCallbacks.size(); i++) {
            KeyguardUpdateMonitorCallback cb = mCallbacks.get(i).get();
            if (cb != null) {
                if (DEBUG || true) Log.d(TAG, "cb != null   mCallbacks.size() = "+mCallbacks.size()+";");
                cb.onTimeFormatChanged(timeFormat);
            }
        }
    }

cb.onTimeFormatChanged(timeFormat);
2.frameworks/base/packages/SystemUI/src/com/android/keyguard/KeyguardStatusViewController.java

    private KeyguardUpdateMonitorCallback mInfoCallback = new KeyguardUpdateMonitorCallback() {
        @Override
        public void onLockScreenModeChanged(int mode) {
            mKeyguardSliceViewController.updateLockScreenMode(mode);
        }

        @Override
        public void onTimeChanged() {
            refreshTime();
        }

        @Override
        public void onTimeFormatChanged(String timeFormat) {
            Log.d("time_12","onTimeFormatChanged");
            mKeyguardClockSwitchController.refreshFormat();
        }

        @Override
        public void onTimeZoneChanged(TimeZone timeZone) {
            mKeyguardClockSwitchController.updateTimeZone(timeZone);
        }

        @Override
        public void onKeyguardVisibilityChanged(boolean showing) {
            if (showing) {
                if (DEBUG) Slog.v(TAG, "refresh statusview showing:" + showing);
                refreshTime();
            }
        }

        @Override
        public void onUserSwitchComplete(int userId) {
            Log.d("time_12","onUserSwitchComplete");
            mKeyguardClockSwitchController.refreshFormat();
        }
    };

在frameworks/base/packages/SystemUI/src/com/android/keyguard/KeyguardUpdateMonitorCallback.java定义了方法

    /**
     * Called when time format changes.
     */
    public void onTimeFormatChanged(String timeFormat) { }

根据mKeyguardClockSwitchController.refreshFormat();

3.frameworks/base/packages/SystemUI/src/com/android/keyguard/KeyguardClockSwitchController.java

    void refreshFormat() {
        Log.d("time_12","refreshFormat    1111");
        if (mClockViewController != null) {
            Log.d("time_12","refreshFormat    2222");
            mClockViewController.refreshFormat();
            mLargeClockViewController.refreshFormat();
        }
    }

mClockViewController.refreshFormat();
4.frameworks/base/packages/SystemUI/src/com/android/keyguard/AnimatableClockController.java

    /**
     * Trigger a time format update
     */
    public void refreshFormat() {
        Log.d("TIME_12","refreshFormat");
        mView.refreshFormat();
    }

mView.refreshFormat();
5.frameworks/base/packages/SystemUI/src/com/android/keyguard/AnimatableClockView.java

    void refreshFormat() {
        Patterns.update(mContext);

        final boolean use24HourFormat = DateFormat.is24HourFormat(getContext());
        Log.d("TIME_12","use24HourFormat  =  "+use24HourFormat+";");
        //context.getUserId()
        Log.d("TIME_12","getUserId  =  "+getContext().getUserId()+";");
        if (mIsSingleLine && use24HourFormat) {
            mFormat = Patterns.sClockView24;
        } else if (!mIsSingleLine && use24HourFormat) {
            mFormat = DOUBLE_LINE_FORMAT_24_HOUR;
        } else if (mIsSingleLine && !use24HourFormat) {
            mFormat = Patterns.sClockView12;
        } else {
            mFormat = DOUBLE_LINE_FORMAT_12_HOUR;
        }

        mDescFormat = use24HourFormat ? Patterns.sClockView24 : Patterns.sClockView12;
        Log.d("TIME_12","mDescFormat  =  "+mDescFormat+";");
        refreshTime();
    }

至此大概能看到打开关闭24小时制开关时，对锁屏界面的一个刷新过程，主用户打开关闭此开关会正常刷新。但是我发现其他用户对此开关的开关，则只会在第一步正常的监听和获取新的小时制12或者24。但是无法响应刷新，也就是在cb.onTimeFormatChanged(timeFormat);处发现对应的方法内的log没打出来。另外在查看frameworks/base/core/java/android/text/format/DateFormat.java里的方法，

    /**
     * Returns true if times should be formatted as 24 hour times, false if times should be
     * formatted as 12 hour (AM/PM) times. Based on the user's chosen locale and other preferences.
     * @param context the context to use for the content resolver
     * @return true if 24 hour time format is selected, false otherwise.
     */
    public static boolean is24HourFormat(Context context) {
        return is24HourFormat(context, context.getUserId());
    }

我发现每次获取的都是主用户的时间格式，context.getUserId()为0。
此问题大概是多用户的设计就是这样的，根本原因我还没查到，只是查看到此流程以及发现这些问题和现象，对比Android12原声机的现象亦是如此。