Add a InteractiveDialog demo for the DialogExtension.

HandyControlDemo/UserControl/Basic/InteractiveDialog.xaml

@@ -0,0 +1,33 @@
+<Border x:Class="HandyControlDemo.UserControl.Basic.InteractiveDialog"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:langs="clr-namespace:HandyControlDemo.Properties.Langs"
+        xmlns:controls="clr-namespace:HandyControl.Controls;assembly=HandyControl"
+        xmlns:interactivity="clr-namespace:HandyControl.Interactivity;assembly=HandyControl"
+        CornerRadius="10"
+        Width="400"
+        Height="247"
+        DataContext="{Binding Path=InteractiveDialog, Source={StaticResource Locator}}"
+        Background="{DynamicResource RegionBrush}">
+    <controls:SimplePanel>
+        <TextBlock Style="{StaticResource TextBlockLargeBold}"
+                   Text="{Binding Message}"
+                   Margin="30"
+                   VerticalAlignment="Top" />
+
+        <TextBox x:Name="TextBox"
+                 Style="{StaticResource TextBoxBaseStyle}"
+                 Text="{x:Static langs:Lang.PleaseInput}"
+                 Margin="70"
+                 VerticalAlignment="Top" />
+        <Button Width="120"
+                Height="32"
+                Command="{Binding CloseCommand}"
+                CommandParameter="{Binding Path=Text, ElementName=TextBox}"
+                Style="{StaticResource ButtonPrimary}"
+                Content="{x:Static langs:Lang.Ok}"
+                HorizontalAlignment="Center"
+                VerticalAlignment="Bottom"
+                Margin="0 0 0 30" />
+    </controls:SimplePanel>
+</Border>