foreground priority的意思|示意

If set, when sending a broadcast the recipient is allowed to run at foreground priority, with a shorter timeout interval.

当发送广播的时候设置了这个标志，会允许接收者以前台的优先级运行，有更短的时间间隔。

Background applications can get events, read and write data, access services, repaint themselves and are generally not restricted other than to run at a lower priority than the foreground application.

转为后台运行的程序照样可以获得系统事件、读写数据、访问系统服务、改变自己的界面，只不过比当前显示在主界面的程序而言，运行优先级低了一点。

Application processes with user-visible or foreground activities are generally given a higher-priority, making camera resource acquisition and use more dependable.

应用程序进程是用户可见或前台活动通常会被给予高优先级，确保相机获取和使用更加可靠。