当我们需要在多个窗体，甚至整个应用程序中使用模板，但是又不想重复定义时，就可以定义以下模板资源，实现模板共享，一般在资源字典中定义资源。
项目源码

资源字典控件模板

创建资源字典：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <!--使用控件模板-->
    <RadialGradientBrush RadiusX="1" RadiusY="5" GradientOrigin="0.5,0.3" x:Key="HighlightBackground">
        <GradientStop Color="White" Offset="0"/>
        <GradientStop Color="Blue" Offset=".4"/>
    </RadialGradientBrush>

    <RadialGradientBrush RadiusX="1" RadiusY="5" GradientOrigin="0.5,0.3" x:Key="PressedBackground">
        <GradientStop Color="White" Offset="0"/>
        <GradientStop Color="Blue" Offset="1"/>
    </RadialGradientBrush>
    
    <SolidColorBrush Color="Blue" x:Key="DefaultBackground">
    </SolidColorBrush>
    <SolidColorBrush Color="Gray" x:Key="DisabledBackground">
    </SolidColorBrush>

    <RadialGradientBrush RadiusX="1" RadiusY="5" GradientOrigin="0.5,0.3" x:Key="Border">
        <GradientStop Color="White" Offset="0"/>
        <GradientStop Color="Blue" Offset="1"/>
    </RadialGradientBrush>


    <ControlTemplate x:Key="GradientButtonTemplate" TargetType="{x:Type Button}">
        <Border x:Name="Border" BorderBrush="{StaticResource Border}" BorderThickness="2" CornerRadius="2" Background="{StaticResource DefaultBackground}" TextBlock.Foreground="White">
            <Grid>
                <Rectangle Name="FocusCue" Visibility="Hidden" Stroke="Black" StrokeThickness="1" StrokeDashArray="1 2" SnapsToDevicePixels="True">
                </Rectangle>
                <ContentPresenter Margin="{TemplateBinding Padding}" RecognizesAccessKey="True">
                </ContentPresenter>
            </Grid>
        </Border>
        <ControlTemplate.Triggers>
            <Trigger Property="IsMouseOver" Value="True">
                <Setter TargetName="Border" Property="Background" Value="{StaticResource HighlightBackground}"/>
            </Trigger>
            <Trigger Property="IsKeyboardFocused" Value="True">
                <Setter TargetName="FocusCue" Property="Visibility" Value="Visible">
                </Setter>
            </Trigger>
            <Trigger Property="IsEnabled" Value="False">
                <Setter TargetName="Border" Property="Background" Value="{StaticResource DisabledBackground}">
                </Setter>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>
</ResourceDictionary>

加入资源

<Window.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="/GradientDictionary.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Window.Resources>

使用资源

Template="{StaticResource GradientButtonTemplate}"