start an activity without changing the background

How do I start a new activi开发者_如何转开发ty in the front keeping the background as it is and the layout of the new activity is a small frame?? I have seen this in some applications where the background becomes a bit blur and the new activity is started right on top of it... how can I implement this??

You can also use a theme dialog for activities, it gives you the look of a dialog and all flexibility of an activity :

In your manifest, when declaring your activity :

<activity android:theme="@android:style/Theme.Dialog">

Regards, Stéphane

Perhaps you are thinking of a popup window? Not necessarily a new activity, though, but you can overlay the window over the one in the background.