android where you want to display the dialog box in the back-office services, how to achieve?

Such as the title, but not in activity in the service in the background.<-! Main posts under Banner (D4) -><-! Posts under the main text (D5) ->
Reply:
The dialog boxes are generally dependent on the activity activity in the background if you want to display a dialog service, it can be: in front of the dialog box show plus the following:

/ / Setup dialog box for the system level, you can not rely on the existence Activity ordinary AlertDialog must be able to call in the Activity class
this.getWindow () setType (WindowManager.LayoutParams.TYPE_SYSTEM_ALERT).;