服务管理类-----KeyguardManager

This method is deprecated. Use FLAG_DISMISS_KEYGUARD and/or FLAG_SHOW_WHEN_LOCKED instead;

this allows you to seamlessly hide the keyguard as your application
moves in and out of the foreground and does not require that any special
permissions be requested. Exit the keyguard securely. The use case for
this api is that, after disabling the keyguard,
your app, which was granted permission to disable the keyguard and show
a limited amount of information deemed safe without the user getting
past the keyguard, needs to navigate to something that is not safe to
view without getting past the keyguard. This
will, if the keyguard is secure, bring up the unlock screen of the
keyguard.

If keyguard screen is showing or in restricted key input mode (i.e.

这是函数用于判断当前是否处于锁屏状态。

This method is deprecated. Use FLAG_DISMISS_KEYGUARD and/or FLAG_SHOW_WHEN_LOCKED instead;

this allows you to seamlessly hide the keyguard as your application
moves in and out of the foreground and does not require that any special
permissions be requested. Enables you to lock or unlock the keyboard.
Get an instance of this class by callingContext.getSystemService().
This class is wrapped by KeyguardManager.

Disable the keyguard from showing.

需要权限android.permission.DISABLE_KEYGUARD

Reenable the keyguard.

如果在此之前调用了disableKeyguard()函数，且在调用disableKeyguard()函数之前是锁屏的话，那么就进行锁屏，否则不进行任何操作。