Applying a FontFamily to all Controls in Silverlight 4 Beta

controls, fonts, silverlight, silverlight-4.0, styles

Solution

The control styling being tied to the type system can be a bit misleading. Its actually based on the value of the controls `DefaultStyleKey` property. In the case of a `Button` the value is `typeof(Button)` and for a `TextBox` it is `typeof(Textbox)`.

A default style will be applied to a control if the `TargetType` value equals the controls `DefaultStyleKey` value. There is no examination of whether the `Type` in the `DefaultStyleKey` is a derivative of the `TargetType`.

Font related properties are a special case since most controls will inherit the values for Font properties from the containing context. Hence you can effectively acheive the same result by specifying `FontFamily` and `FontWeight` on the UserControl element.

Edit

From a comment by the OP:-

I was hoping that I could set it in one place and have every UserControl in the entire application take on that style.

The closest you can get to that is to place a keyed style in the app resources and ensure all the usercontrols bind to that style. Of course this still requires some co-operation for each user control but at least the font choices remain in a single place.

For example in app.xaml:-

<Style x:Key="Common" TargetType="UserControl">
    <Setter Property="FontFamily" Value="Arial" />
    <Setter Property="FontWeight" Value="Bold" />
<Setter Property="Foreground" Value="Blue" />

Then in each usercontrol:-

<UserControl ...namespace stuff here...
   Style="{StaticResource Common}">
  <!-- ... content here ... -->

Problem

I'd like to give every `Control` a certain `FontFamily` and `FontWeight` in Silverlight 4.0. I know that styles can now apply to all controls of a certain type, so I tried this: ``` <Style TargetType="Control"> <Setter Property="FontFamily" Value="Arial" /> <Setter Property="FontWeight" Value="Bold" /> </Style> ``` Unfortunately, that doesn't appear to work. I can do this for types that derive from `Control`, however. For example, setting `TargetType` to `Button` applies those values to every `Button` in my application. Why can't I do this for the `Control` base class, then?

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