WPF

<EventTrigger RoutedEvent="Button.Click">
    <BeginStoryboard>
        <Storyboard  >
            <DoubleAnimation Storyboard.TargetProperty="Width" To="0" Duration="0:0:0"/>
            <DoubleAnimation BeginTime="0:0:01" Storyboard.TargetProperty="Width" To="210" Duration="0:0:0"/>
        </Storyboard>
    </BeginStoryboard>
</EventTrigger>

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Threading;

namespace WpfTabSample
{
    public class AnimatedTabControl : TabControl
    {
        public static readonly RoutedEvent SelectionChangingEvent = EventManager.RegisterRoutedEvent(
            "SelectionChanging", RoutingStrategy.Direct, typeof(RoutedEventHandler), typeof(AnimatedTabControl));

        private DispatcherTimer timer;

        public AnimatedTabControl()
        {
            DefaultStyleKey = typeof(AnimatedTabControl);
        }

        public event RoutedEventHandler SelectionChanging
        {
            add { AddHandler(SelectionChangingEvent, value); }
            remove { RemoveHandler(SelectionChangingEvent, value); }
        }

        protected override void OnSelectionChanged(SelectionChangedEventArgs e)
        {
            this.Dispatcher.BeginInvoke(
                (Action)delegate
                {
                    this.RaiseSelectionChangingEvent();

                    this.StopTimer();

                    this.timer = new DispatcherTimer { Interval = new TimeSpan(0, 0, 0, 0, 500) };

                    EventHandler handler = null;
                    handler = (sender, args) =>
                    {
                        this.StopTimer();
                        base.OnSelectionChanged(e);
                    };
                    this.timer.Tick += handler;
                    this.timer.Start();
                });
        }

        // This method raises the Tap event 
        private void RaiseSelectionChangingEvent()
        {
            var args = new RoutedEventArgs(SelectionChangingEvent);
            RaiseEvent(args);
        }

        private void StopTimer()
        {
            if (this.timer != null)
            {
                this.timer.Stop();
                this.timer = null;
            }
        }
    }
}

<UserControl x:Class="WpfTabSample.RoundedBox"
             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" 
             xmlns:local="clr-namespace:WpfTabSample"
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <Grid Margin="-6,-5,-12,-13">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="20"/>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="27"/>
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="20"/>
                <RowDefinition Height="*"/>
                <RowDefinition Height="27"/>
            </Grid.RowDefinitions>
            <!--<Image Height="20" Width="20" Source="../Resources/shadow_tl.png" Stretch="Fill"/>
            <Image Height="20" Grid.Column="1" Source="../Resources/shadow_t.png" Stretch="Fill"/>
            <Image Height="20" Width="27" Grid.Column="2" Source="../Resources/shadow_tr.png" Stretch="Fill"/>
            <Image Width="27" Grid.Column="2" Grid.Row="1" Source="../Resources/shadow_r.png" Stretch="Fill"/>
            <Image Width="20" Grid.Row="1" Source="../Resources/shadow_l.png" Stretch="Fill"/>
            <Image Height="27" Grid.Column="1" Grid.Row="2" Source="../Resources/shadow_b.png" Stretch="Fill" />
            <Image Height="27" Width="20" Grid.Row="2" Source="../Resources/shadow_bl.png" Stretch="Fill"/>
            <Image Height="27" Width="27" Grid.Column="2" Grid.Row="2" Source="../Resources/shadow_br.png" Stretch="Fill"/>-->
        </Grid>
        <Border Background="#99FFFFFF" Opacity="0.8" CornerRadius="12,12,12,12" VerticalAlignment="Stretch" />
    </Grid>
</UserControl>

<Window x:Class="WpfTabSample.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:Controls="clr-namespace:WpfTabSample"
        mc:Ignorable="d" UseLayoutRounding="True"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <SolidColorBrush x:Key="TabControlNormalBorderBrush" Color="#8C8E94"/>

        <Style TargetType="Controls:AnimatedTabControl">
            <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
            <Setter Property="Padding" Value="4,4,4,4"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="BorderBrush" Value="{StaticResource TabControlNormalBorderBrush}"/>
            <Setter Property="Background" Value="#F9F9F9"/>
            <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            <Setter Property="VerticalContentAlignment" Value="Stretch"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="Controls:AnimatedTabControl">

                        <Grid ClipToBounds="true" KeyboardNavigation.TabNavigation="Local">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto"/>
                                <RowDefinition Height="*"/>
                            </Grid.RowDefinitions>

                            <Border Height="30" Margin="10,0,10,10"  HorizontalAlignment="Left" VerticalAlignment="Top" Width="Auto" Grid.Row="1" CornerRadius="12,12,12,12" Background="{TemplateBinding Background}" BorderThickness="2,2,2,2" BorderBrush="#FFFFFFFF">
                                <TabPanel x:Name="HeaderPanel" HorizontalAlignment="Center" VerticalAlignment="Center" IsItemsHost="true" Grid.Column="0" Grid.Row="0" KeyboardNavigation.TabIndex="1"/>
                            </Border>

                            <Grid Grid.Row="1" Margin="0,40,0,0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                                <Viewport3D x:Name="vp3D" Visibility="Hidden" Width="Auto" Height="Auto">
                                    <Viewport3D.Camera>
                                        <PerspectiveCamera x:Name="camera" Position="0,0,0.5" LookDirection="0,0,-1" FieldOfView="90" />
                                    </Viewport3D.Camera>
                                    <Viewport3D.Children>
                                        <ModelVisual3D>
                                            <ModelVisual3D.Content>
                                                <Model3DGroup>
                                                    <DirectionalLight Color="#444" Direction="0,0,-1" />
                                                    <AmbientLight Color="#BBB" />
                                                </Model3DGroup>
                                            </ModelVisual3D.Content>
                                        </ModelVisual3D>
                                        <ModelVisual3D>
                                            <ModelVisual3D.Content>
                                                <GeometryModel3D>
                                                    <GeometryModel3D.Geometry>
                                                        <MeshGeometry3D  TriangleIndices="0,1,2 2,3,0" TextureCoordinates="0,1 1,1 1,0 0,0" Positions="-0.5,-0.5,0 0.5,-0.5,0 0.5,0.5,0 -0.5,0.5,0" />
                                                    </GeometryModel3D.Geometry>
                                                    <GeometryModel3D.Material>
                                                        <DiffuseMaterial>
                                                            <DiffuseMaterial.Brush>
                                                                <VisualBrush Visual="{Binding ElementName=BorderIn}" Stretch="Uniform" />
                                                            </DiffuseMaterial.Brush>
                                                        </DiffuseMaterial>
                                                    </GeometryModel3D.Material>
                                                    <GeometryModel3D.BackMaterial>
                                                        <DiffuseMaterial>
                                                            <DiffuseMaterial.Brush>
                                                                <VisualBrush Visual="{Binding ElementName=BorderIn}" Stretch="Uniform">
                                                                    <VisualBrush.RelativeTransform>
                                                                        <ScaleTransform ScaleX="-1" CenterX="0.5" />
                                                                    </VisualBrush.RelativeTransform>
                                                                </VisualBrush>
                                                            </DiffuseMaterial.Brush>
                                                        </DiffuseMaterial>
                                                    </GeometryModel3D.BackMaterial>
                                                    <GeometryModel3D.Transform>
                                                        <RotateTransform3D>
                                                            <RotateTransform3D.Rotation>
                                                                <AxisAngleRotation3D x:Name="rotate" Axis="0,3,0" Angle="0" />
                                                            </RotateTransform3D.Rotation>
                                                        </RotateTransform3D>
                                                    </GeometryModel3D.Transform>
                                                </GeometryModel3D>
                                            </ModelVisual3D.Content>
                                        </ModelVisual3D>
                                    </Viewport3D.Children>
                                </Viewport3D>
                                <Border x:Name="BorderOut" VerticalAlignment="Stretch">
                                    <Border x:Name="BorderIn" VerticalAlignment="Stretch" Background="#00000000" >
                                        <Grid>
                                            <Controls:RoundedBox Margin="10" />
                                            <ContentPresenter x:Name="PART_SelectedContentHost" ContentSource="SelectedContent" Margin="20"/>
                                        </Grid>
                                    </Border>
                                </Border>
                            </Grid>
                        </Grid>

                        <ControlTemplate.Triggers>
                            <EventTrigger RoutedEvent="Controls:AnimatedTabControl.SelectionChanging">
                                <BeginStoryboard>
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="vp3D"  Storyboard.TargetProperty="Visibility">
                                            <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="{x:Static Visibility.Visible}" />
                                            <DiscreteObjectKeyFrame KeyTime="0:0:1.1" Value="{x:Static Visibility.Hidden}" />
                                        </ObjectAnimationUsingKeyFrames>
                                        <DoubleAnimation To="0" Duration="0:0:0.05" Storyboard.TargetName="BorderOut" Storyboard.TargetProperty="Opacity" />
                                        <DoubleAnimation BeginTime="0:0:1.05" Duration="0:0:0.05" To="1" Storyboard.TargetName="BorderOut" Storyboard.TargetProperty="Opacity" />
                                        <Point3DAnimation To="0,0,1.1" From="0,0,0.5"  BeginTime="0:0:0.05" Duration="0:0:0.5" AutoReverse="True" DecelerationRatio="0.3"  Storyboard.TargetName="camera" 

                                            Storyboard.TargetProperty="(PerspectiveCamera.Position)" />
                                        <DoubleAnimation From="0" To="180" AccelerationRatio="0.3" DecelerationRatio="0.3" BeginTime="0:0:0.05" Duration="0:0:1"  Storyboard.TargetName="rotate" Storyboard.TargetProperty="Angle" />
                                    </Storyboard>
                                </BeginStoryboard>
                            </EventTrigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>


                </Setter.Value>
            </Setter>
        </Style>
    </Window.Resources>
    <Grid>
        <Controls:AnimatedTabControl>
            <TabItem Header="One" />
            <TabItem Header="Two" />
            <TabItem Header="Three" />
        </Controls:AnimatedTabControl>
    </Grid>
</Window>

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Interactivity;

namespace WpfSimpleReflectionAssistant
{
    //Code from:
    //https://social.msdn.microsoft.com/Forums/silverlight/en-US/5cd586e7-640f-447b-9040-e9270173abf7/passing-drop-event-data-in-a-command-parameter-using-mvvm-and-the-interactivity-framework?forum=silverlightmvvm
    public sealed class EventCommand : TriggerAction<DependencyObject>
    {

        public static readonly DependencyProperty CommandParameterProperty =
            DependencyProperty.Register("CommandParameter", typeof(object), typeof(EventCommand), null);


        public static readonly DependencyProperty CommandProperty = DependencyProperty.Register(
            "Command", typeof(ICommand), typeof(EventCommand), null);


        public static readonly DependencyProperty InvokeParameterProperty = DependencyProperty.Register(
            "InvokeParameter", typeof(object), typeof(EventCommand), null);

        private string commandName;

        public object InvokeParameter
        {
            get
            {
                return this.GetValue(InvokeParameterProperty);
            }
            set
            {
                this.SetValue(InvokeParameterProperty, value);
            }
        }


        public ICommand Command
        {
            get
            {
                return (ICommand)this.GetValue(CommandProperty);
            }
            set
            {
                this.SetValue(CommandProperty, value);
            }
        }

        public string CommandName
        {
            get
            {
                return this.commandName;
            }
            set
            {
                if (this.CommandName != value)
                {
                    this.commandName = value;
                }
            }
        }

        public object CommandParameter
        {
            get
            {
                return this.GetValue(CommandParameterProperty);
            }

            set
            {
                this.SetValue(CommandParameterProperty, value);
            }
        }

        public object Sender { get; set; }

        protected override void Invoke(object parameter)
        {
            this.InvokeParameter = parameter;
            if (this.AssociatedObject != null)
            {
                ICommand command = this.Command;
                if ((command != null) && command.CanExecute(this.CommandParameter))
                {
                    if (this.CommandParameter.GetType() == typeof(Canvas))
                    {
                        Canvas myCanvas = (Canvas)this.CommandParameter;
                        Point pass = Mouse.GetPosition(myCanvas);
                        command.Execute(pass);
                    }
                    else
                        command.Execute(this.CommandParameter);
                }
            }
        }
    }
}