ResourceDictionary shared variable

Question

In my ResourceDictionary Resource_Color I have defined this row:

    <Color x:Key="MainColor">Black</Color>

Now, I want to use this MainColor in another resource file, for example Resource_DataGrid.

        <Style.Triggers>
        <Trigger Property="IsSelected" Value="True">
            <Setter Property="Foreground" Value="{StaticResource MainColor}" />

. . . In this mode doesn't work. How can I write this declaration ?

Answer 1

Use ResourceDictionary.MergedDictionaries

Window1.xaml

<Window x:Class="Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Window1" Height="Auto" Width="Auto">
  <Window.Resources>
    <ResourceDictionary Source="Dictionary2.xaml" />
  </Window.Resources>
  <Grid>
    <TextBox Text="TESTING" FontWeight="Bold" Margin="30" />
  </Grid>
</Window>

Dictionary1.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <Color x:Key="MainColor">Blue</Color>
  <SolidColorBrush x:Key="MainBrush" Color="{StaticResource MainColor}" />
</ResourceDictionary>

Dictionary2.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="Dictionary1.xaml" />
  </ResourceDictionary.MergedDictionaries>

  <Style TargetType="TextBox">
    <Setter Property="Foreground" Value="{StaticResource MainBrush}" />
  </Style>
</ResourceDictionary>

Also, the Foreground property is usually a Brush, not a Color. My example shows it.