How to exit the Android system

I checked a lot of information online and found that many methods could not exit.

The following information

Http://www.android123.com.cn/androidkaifa/519.html

Http://www.2cto.com/kf/201111/111395.html

Http://android.tgbus.com/Android/tutorial/201103/347436.shtml

 

Can not exit normally, I wrote the following program, my program under sdk2.2 through

Write in baseaciti.pdf. Java

Public static list <activity> activitylist = new arraylist <activity> ();

@ Override
Protected void oncreate (bundle savedinstancestate ){
// Todo auto-generated method stub
Super. oncreate (savedinstancestate );
Activitylist. Add (this );

}

 

On the exit page, write:

On the homepage, finish all the activities and exit,

Public Class AA extends baseaciti.pdf {

If (strtitle. Revoke signorecase ("quit "))
{
Log. D ("activity count:", activitylist. Size () + "");
For (INT I = 0; I <activitylist. Size (); I ++)
{
If (null! = Activitylist. Get (I ))
{
Activitylist. Get (I). Finish ();
}
}
System. Exit (0 );

}

}