Use Custom Background Image for Application-為自己的Windows Phone程式使用自訂背景圖片

If you want to use a custom image for your application background, you can set this as follows:

 

<phone:PhoneApplicationPage >  ...  <Grid x:Name="LayoutRoot">    <Grid.Background>      <ImageBrush ImageSource="/Images/YourImage.jpg"></ImageBrush>    </Grid.Background>    ...  </Grid></phone:PhoneApplicationPage>

Some things to note:

• Make sure the Image has the Build Action set to Content.
• Make sure the Images folder is at the application root level.
• Having your own background and colour combination will have the same look across bothLight and
  Dark themes.

 原文連結：http://amitchandnz.wordpress.com/2011/09/26/use-custom-background-image-for-application/