客户定制需求:

能够动态控制系统的通知显示<隐藏>在状态栏

大致修改如下：

找到处理通知栏的代码位置：

frameworks\base\services\core\java\com\android\server\notification\NotificationManagerService.java

每次通知都会调用到这里，用以显示通知在状态栏

void enqueueNotificationInternal(final String pkg, final String opPkg, final int callingUid,
            final int callingPid, final String tag, final int id, final Notification notification,
            int incomingUserId) {

因此可以在enqueueNotificationInternal 方法中添加如下判断：如果当前的通知栏是显示状态则显示，否则跳过显示通知操作。<Settings.Secure.NOTIFICATION_ENABLED :添加到settings数据库中的字段，需要自行添加>

int value = android.provider.Settings.Secure.getInt(getContext().getContentResolver(), android.provider.Settings.Secure.NOTIFICATION_ENABLED, 0);       
        if(value==1){
            return;
        } 

定义settings NOTIFICATION_ENABLED观察者,监听值的变化，控制通知栏的显示或隐藏

ContentObserver mContentOb = new ContentObserver(new Handler()) {
    
        @Override
        public void onChange(boolean selfChange) {
            
            int value = android.provider.Settings.Secure.getInt(getContext().getContentResolver(), android.provider.Settings.Secure.NOTIFICATION_ENABLED, 0);       
            if(value == 1){ 
                setNotificationHideByUser(true);
            }else{
                setNotificationHideByUser(false);
            }
        }
    };
    

注册settings观察者，监听NOTIFICATION_ENABLED 的值

private final class SettingsObserver extends ContentObserver {
···

void observe() {
            ContentResolver resolver = getContext().getContentResolver();
            resolver.registerContentObserver(NOTIFICATION_BADGING_URI,
                    false, this, UserHandle.USER_ALL);
            resolver.registerContentObserver(NOTIFICATION_LIGHT_PULSE_URI,
                    false, this, UserHandle.USER_ALL);
            resolver.registerContentObserver(NOTIFICATION_RATE_LIMIT_URI,
                    false, this, UserHandle.USER_ALL);
            update(null);
            /** add by 1900 for hide or show notification*/
              resolver.registerContentObserver(Settings.Secure.getUriFor(Settings.Secure.NOTIFICATION_ENABLED),false, mContentOb);  
           /* add end */
        }
···

定义处理通知栏显示隐藏的方法：遍历所有在队列中的通知，并显示或者隐藏

private void setNotificationHideByUser(boolean isHide){     
        Log.d("1900","setNotificationHideByUser start isHide " +isHide);
        int size = mNotificationList.size();
        List<NotificationRecord> changedNotifications = new ArrayList<>();
        for(int i=0;i<size;i++){            
            NotificationRecord rec = mNotificationList.get(i);               
            rec.setHidden(isHide);
            changedNotifications.add(rec);    
        }
        if(isHide)
            mListeners.notifyHiddenLocked(changedNotifications);
        else
            mListeners.notifyUnhiddenLocked(changedNotifications);
    }