How to set a background image by code on windows phone? - windows-phone-8

Question

My question is very simple but I don't find a solution that works.
I code a Windows Phone app and I have to change the background. The change depends of the user profile on the application. If the user is a male, the app display a blue background, if she is a female, a pink one.
I've tried to bind the background but I still have a blink effect (black to the background image).
It is very visible when the app navigates between two pages but invisible when the change is made on the same page.
I tried these solutions too but the background stay black:
string uri = String.Format("/Assets/Background{0}.png", App.Context.SelectedUser.IsMan ? "Boy" : "Girl");
var imageBrush = new System.Windows.Media.ImageBrush
{
ImageSource = new BitmapImage(new Uri(uri, UriKind.Relative))
};
this.Background = imageBrush;
string uri = String.Format("/Assets/Background{0}.png", App.Context.SelectedUser.IsMan ? "Boy" : "Girl");
var imageBrush = new System.Windows.Media.ImageBrush
{
ImageSource = new BitmapImage(new Uri(uri, UriKind.Relative))
};
App.RootFrame.Background = imageBrush;
I tried with .jpg and .png image file but none works.
Is my code wrong?
Anyone has a suggestion?
Thanks a lot :-)

Answer 1

This code works in a blank silverlight app in Windows Phone 8.
In Xaml:
<Grid x:Name="LayoutRoot" >
<Grid.Background>
<ImageBrush ImageSource="/Assets/boy.png" Stretch="UniformToFill" />
</Grid.Background>
<Button Content="Change" Click="Button_Click" />
</Grid>
and in the code behind:
private void Button_Click(object sender, RoutedEventArgs e)
{
System.Windows.Media.Imaging.BitmapImage bmp = new System.Windows.Media.Imaging.BitmapImage();
bmp.UriSource = new Uri("/Assets/girl.png", UriKind.Relative);
var imageBrush = new System.Windows.Media.ImageBrush
{
ImageSource = bmp
};
LayoutRoot.Background = imageBrush;
}