我有一个函数可以确定手机屏幕的四种状态:屏幕打开、屏幕关闭、屏幕打开并锁定、屏幕打开但未锁定。我的功能是privateKeyguardManagerkeyguardManager;publicStringgetScreenStatus(){Stringsreen_State="unknown";keyguardManager=(KeyguardManager)getSystemService(KEYGUARD_SERVICE);PowerManagerpm=(PowerManager)getApplicationContext().getSystemService(Context.PO