android activity back stack

I have 5 activity in back stack. At a time, I want to remove 4 child activity from back stack. how can I do this? i dont want to finish each activity by hand. is there any method wh开发者_JAVA百科ich can make my back stack empty?

You can start your fifth activity with the FLAG_ACTIVITY_CLEAR_TOP flag.

What you want is essentially being able to end application from any other activity different from the first one.

What I do is using an application variable determining if application must be shutdown and then check it on the onresume method.

protected void onResume()
{
        super.onResume();
        if (!getMyApplication().isPlatformActive())
        { 
              /* We finish every activity after resuming if we must shutdown application */
              finish();
        }
}

boolean isRootScreen()
{
        /* Every activity will override this and set it to true if want to exit application from here */
        return false; 
}

protected void onBackPressed()
{
        if(isRootScreen())
        { 
            /* You could show a confirmation dialog here */
            getMyApplication().setPlatformActive(false);
        }
        super.onBackPressed();
}