Add DialogHost.DialogContentUniformCornerRadius (#3103)

* Add DialogHost.DialogContentUniformCornerRadius

Allows users of DialogHost to specify a custom (uniform) corner radius for the nested Card

* Update MaterialDesignThemes.Wpf/DialogHost.cs

---------

Co-authored-by: Kevin B <Keboo@users.noreply.github.com>

Author: nicolaihenriksen

MainDemo.Wpf/Dialogs.xaml

@@ -62,7 +62,8 @@
                         UniqueKey="dialogs_sample1">
         <materialDesign:DialogHost DialogClosed="Sample1_DialogHost_OnDialogClosed"
                                    DialogClosing="Sample1_DialogHost_OnDialogClosing"
-                                   DialogTheme="Inherit">
+                                   DialogTheme="Inherit"
+                                   DialogContentUniformCornerRadius="20">
           <materialDesign:DialogHost.DialogContent>
             <StackPanel Margin="16">
               <TextBlock Text="Add a new fruit." />

MaterialDesignThemes.Wpf/DialogHost.cs

@@ -432,6 +432,15 @@ public object? DialogContent
             set => SetValue(DialogContentProperty, value);
         }
 
+        public static readonly DependencyProperty DialogContentUniformCornerRadiusProperty = DependencyProperty.Register(
+            nameof(DialogContentUniformCornerRadius), typeof(double), typeof(DialogHost), new PropertyMetadata(4d));
+
+        public double DialogContentUniformCornerRadius
+        {
+            get => (double)GetValue(DialogContentUniformCornerRadiusProperty);
+            set => SetValue(DialogContentUniformCornerRadiusProperty, value);
+        }
+
         public static readonly DependencyProperty DialogContentTemplateProperty = DependencyProperty.Register(
             nameof(DialogContentTemplate), typeof(DataTemplate), typeof(DialogHost), new PropertyMetadata(default(DataTemplate)));
 

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.DialogHost.xaml

@@ -173,7 +173,7 @@
                           RenderTransformOrigin=".5,.5"
                           Tag="{TemplateBinding DialogBackground}"
                           TextElement.Foreground="{DynamicResource MaterialDesignBody}"
-                          UniformCornerRadius="4">
+                          UniformCornerRadius="{TemplateBinding DialogContentUniformCornerRadius}">
                   <wpf:Card.Style>
                     <Style TargetType="wpf:Card" BasedOn="{StaticResource {x:Type wpf:Card}}">
                       <Setter Property="Background" Value="{Binding Tag, RelativeSource={RelativeSource Self}}" />
@@ -418,7 +418,7 @@
                         RenderTransformOrigin=".5,.5"
                         Tag="{TemplateBinding DialogBackground}"
                         TextElement.Foreground="{DynamicResource MaterialDesignBody}"
-                        UniformCornerRadius="4">
+                        UniformCornerRadius="{TemplateBinding DialogContentUniformCornerRadius}">
                 <wpf:Card.RenderTransform>
                   <TransformGroup>
                     <ScaleTransform x:Name="CardScaleTransform" ScaleX="0" ScaleY="0" />
@@ -478,4 +478,4 @@
       </Trigger>
     </Style.Triggers>
   </Style>
-</ResourceDictionary>
+</ResourceDictionary>