Activity as dialog: Place in top left corner

Question

I'm trying to place an Android activity that uses the Holo.Dialog theme in the top left corner of my application by using the following code in OnCreate():

var layoutParams = this.Window.Attributes;
layoutParams.Gravity = GravityFlags.Top | GravityFlags.Left;

(This is Mono for Android)

It kind of works, however there is a tiny gap between the actual corner and the beginning of my dialog, which you can see in the following screen shot:

https://www.dropbox.com/s/cyy9lglq5642nz1/device-2013-05-26-223855.png

Notice the gap between the menu box and the actual edge of the screen. What can I do to remove that gap completly?

Answer 1

Turns out the problem is rather simple: Theme.Holo.Dialog defines a background that adds a transparent border around the dialog. This causes the spacing between the corner and the dialog.

Creating a custom style fixes it:

<style name="MyCustomDialog" parent="android:Theme.Holo.Dialog">
    <item name="android:windowBackground">@null</item>
</style>

This overwrites the background and removes the spacing.