Android development: exit the program (dialog box, two return keys Exit)

PostCode:

 Public   Void  Exitclick (view) {alertdialog. Builder AA = New Alertdialog. Builder ( This  ); AA. settitle ( "Message prompt" ); AA. setmessage ( "Are you sure you want to exit? " ); AA. seticon (R. drawable. Icon); AA. setpositivebutton ( "OK ", New  Dialoginterface. onclicklistener () {@ override Public   Void Onclick (dialoginterface dialog, Int  Which ){  //  Todo auto-generated method stub Mainactivity. This  . Finish () ;}}); AA. setnegativebutton ( "Cancel ", Null  ); AA. Create (); AA. Show ();  //  This. Finish (); }

It feels more complicated than C...

In addition, press the return key to exit and paste the Code:

 Private   Void  Exitdialog () {alertdialog. Builder AA = New Alertdialog. Builder ( This  ); AA. settitle ( "Message prompt" ); AA. setmessage ( "Are you sure you want to exit? " ); AA. seticon (R. drawable. Icon); AA. setpositivebutton ( "OK ", New  Dialoginterface. onclicklistener () {@ override  Public  Void Onclick (dialoginterface dialog, Int  Which ){  //  Todo auto-generated method stub Mainactivity. This  . Finish () ;}}); AA. setnegativebutton ( "Cancel ", Null  ); AA. Create (); AA. Show () ;}@ override  Public   Boolean Onkeydown ( Int Keycode, keyevent event ){  If (Keycode = Keyevent. keycode_back) {exitdialog ();}  Return   True  ;} 

It is also popular to exit with two consecutive responses. Code:

     Private   Static   Boolean Isexit = False  ;  Private   Static   Boolean Hastask = False  ; Timer texit = New  Timer (); timertask task = New  Timertask () {@ override  Public   Void  Run (){  //  Todo auto-generated method stub Isexit = False  ; Hastask =True  ;}}; @ Override  Public   Boolean Onkeydown ( Int  Keycode, keyevent event ){  If (Keycode = Keyevent. keycode_back ){  //  Exitdialog ();              If (Isexit = False  ) {Isexit = True ; Toast. maketext (  This , "Exit once again Program " , Toast. length_short). Show ();  If (! Hastask) {texit. Schedule (task, 2000 );}}  Else  {Finish (); system. Exit ( 0 );}}  // Return true;          Return   False  ;}