Custom back key (Implementation press two return key to exit the program)

Implementation mechanism: When the user clicks on the physical return key, the activity calls onbackpressed (), simply by copying the method in the activity

Here is the code implementation:

1  PackageCom.example.qjm3662.service_learn;2 3 ImportAndroid.content.ComponentName;4 Importandroid.content.Intent;5 Importandroid.content.ServiceConnection;6 ImportAndroid.os.IBinder;7 Importandroid.support.v7.app.AppCompatActivity;8 ImportAndroid.os.Bundle;9 ImportAndroid.view.Window;Ten ImportAndroid.widget.TimePicker; One ImportAndroid.widget.Toast; A  -  Public classMainactivityextendsappcompatactivity { -  the     //A static tag that identifies whether the user has continuously clicked the back button two times within the specified time -     Static intEvent_back = 0; - @Override -     protected voidonCreate (Bundle savedinstancestate) { +         Super. OnCreate (savedinstancestate); - Setcontentview (r.layout.activity_main); +     } A  at @Override -      Public voidonbackpressed () { -         //If the user clicks the Back button continuously within two seconds, the default action is performed (typically ejecting the activity stack in the current activity) -         if(Event_back = = 1){ -             Super. onbackpressed (); -}Else{ in             //user First Click, set Event_back to 1 to indicate that the user has clicked once -Event_back = 1; to             //pop up the toast box to remind the user to exit the program at one click +Toast.maketext (mainactivity. This, "Press again to exit", Toast.length_short). Show (); -Timepicker Timepicker =NewTimepicker ( This); the             //If the user does not click the Back button again within two seconds, the event_back is reset to 0, the user needs to re-click two times *Timepicker.postdelayed (NewRunnable () { $ @OverridePanax Notoginseng                  Public voidrun () { -Event_back = 0; the                 } +},2000); A         } the     } +}

Custom back key (Implementation press two return key to exit the program)