I am writing a style for a custom control derived directly from Control. Visual Studio places the style for a "Custom Control (WPF)" in the Themes\generic.xaml file. My style contains an image which I can't get displayed, seems there's something special about how to set the Source for an image from within the generic.xaml file.
I managed to reproduce the issue with a simpler scenario. Create a "WPF Custom Control library" then add a style for buttons like so, in the themes\generic.xaml . Here's my complete generic.xaml:
<ResourceDictionary
...
<Style TargetType="{x:Type Button}">
<Setter Property="Content">
<Setter.Value>
<Image Source="SmallHandle.png"></Image>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
After this I have create a UserControl (in the same project) containing just a button (for the sake of testing out the style) like so:
<UserControl x:Class="BlendControls.UserControl1"
...
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Button/>
</UserControl>
I have added the SmallHandle.png in the root project directory, in the themes directory, I have added it also to the good old Resources page, tried changing the build action to resource, embedded resource, tried copying the image manually to the build directory, but to no effect. The image is never displayed.
This must be related to the generic.xaml file, because copying the entire style to the same file where the Button is placed works fine. That is, the following works as expected:
<UserControl x:Class="BlendControls.UserControl1"
...
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
<Style TargetType="{x:Type Button}">
<Setter Property="Content">
<Setter.Value>
<Image Source="SmallHandle.png"></Image>
</Setter.Value>
</Setter>
</Style>
</UserControl.Resources>
<Button></Button>
</UserControl>
So, how should I set the Source of images from generic.xaml? Or alternatively, where should I put the styles/templates for custom controls?
---- Solution ----
As pointed out by Sheridan, I have to use the "full" pack URI notation as:
pack://application,,,/MyAssembly;components/SmallHandle.png
This looks strange to me, as the image is in the same assembly. Not sure, looks like I am referencing from outside the dll.