support for .NET framework 3.5

Still have bugs

Net35/HandyControlDemo_Net35/UserControl/Basic/Avatar.xaml

@@ -0,0 +1,22 @@
+<UserControl x:Class="HandyControlDemo.UserControl.Avatar"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             Margin="16"
+             Effect="{StaticResource EffectShadow5}" 
+             Cursor="Hand"
+             mc:Ignorable="d">
+    <Button Style="{StaticResource ButtonCustom}" Click="ButtonAvatar_OnClick">
+        <Border Background="{DynamicResource SecondaryRegionBrush}" CornerRadius="10">
+            <Grid>
+                <Grid.RowDefinitions>
+                    <RowDefinition/>
+                    <RowDefinition Height="Auto"/>
+                </Grid.RowDefinitions>
+                <Image Source="{Binding Source,RelativeSource={RelativeSource AncestorType=UserControl}}" Height="120" Width="120" Stretch="Uniform" Margin="10"/>
+                <TextBlock TextTrimming="CharacterEllipsis" TextWrapping="NoWrap" Margin="0,0,0,10" Grid.Row="1" Style="{StaticResource TextBlockDefault}" Text="{Binding UserName,RelativeSource={RelativeSource AncestorType=UserControl}}"></TextBlock>
+            </Grid>
+        </Border>
+    </Button>
+</UserControl>

Net35/HandyControlDemo_Net35/UserControl/Basic/Avatar.xaml.cs

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+using System.Diagnostics;
+using System.Windows;
+using System.Windows.Media.Imaging;
+
+
+namespace HandyControlDemo.UserControl
+{
+    public partial class Avatar
+    {
+        public Avatar()
+        {
+            InitializeComponent();
+        }
+
+        public static readonly DependencyProperty SourceProperty = DependencyProperty.Register(
+            "Source", typeof(BitmapFrame), typeof(Avatar), new PropertyMetadata(default(BitmapFrame)));
+
+        public BitmapFrame Source
+        {
+            get => (BitmapFrame) GetValue(SourceProperty);
+            set => SetValue(SourceProperty, value);
+        }
+
+        public static readonly DependencyProperty UserNameProperty = DependencyProperty.Register(
+            "UserName", typeof(string), typeof(Avatar), new PropertyMetadata(default(string)));
+
+        public string UserName
+        {
+            get => (string) GetValue(UserNameProperty);
+            set => SetValue(UserNameProperty, value);
+        }
+
+        public static readonly DependencyProperty LinkProperty = DependencyProperty.Register(
+            "Link", typeof(string), typeof(Avatar), new PropertyMetadata(default(string)));
+
+        public string Link
+        {
+            get => (string) GetValue(LinkProperty);
+            set => SetValue(LinkProperty, value);
+        }
+
+        private void ButtonAvatar_OnClick(object sender, RoutedEventArgs e) => Process.Start(Link);
+    }
+}