Back Button handling in blackberry - blackberry

Question

I want to come to home screen when clicking on the back button from my application in blackberry. I have searched for this in google and stackoverflow, But I didn't get any solution. Anybody help for this.
In My Starting Screen i wrote like this for back button.
protected boolean keyDown(int keycode, int time)
{
if (Keypad.key(keycode) == Keypad.KEY_ESCAPE)
{
close();
return true;
}
else
{
return super.keyDown(keycode, time);
}
}
In my HomeScreen i wrote like this.
protected boolean keyDown(int keycode, int time)
{
if (Keypad.key(keycode) == Keypad.KEY_ESCAPE)
{
UiApplication.getUiApplication().pushScreen(new StartingScreen());
return true;
}
else
{
return super.keyDown(keycode, time);
}
}
From my application HomeScreen I am able to come to starting screen of the my application. after that when i click on back button from starting screen i need to go to blackberry home screen that means i need to exit the app and come out of that. I wrote close(); to come to blackberry home screen. but its not working. it is again coming to my application homescreen.

Answer 1

Override keyDown method in your subclass of MainScreen.
protected boolean keyDown(int keycode, int time) {
int key = Keypad.key(keycode);
if(key==Characters.ESCAPE){
// do something here
return true;
}
return super.keyDown(keycode, time);
}
To come to home screen
while(!(UiApplication.getUiApplication().getActiveScreen() instanceof HomeScreen)){
UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
}

Answer 2

I got the Solution... i have written lik this.
public boolean onClose()
{
int choose=Dialog.ask(Dialog.D_YES_NO, "Are you sure Want to Exit?");
if(choose==Dialog.YES)
{
System.exit(0);
}
return true;
}

Answer 3

Try this -
public class yourclass extends MainScreen{
public yourclass(){
}
}
public boolean onClose() {
Application.getApplication().invokeLater(new Runnable() {
public void run() {
//close this screen and push your home screen
}
});
return true;
}