<Binding>

  <Binding.RelativeSource>

    <RelativeSource Mode="modeEnumValue"/>

  </Binding.RelativeSource>

</Binding>

- or

<Binding>

  <Binding.RelativeSource>

    <RelativeSource

      Mode="FindAncestor"

      AncestorType="{x:Type typeName}"

      AncestorLevel="intLevel"

    />

  </Binding.RelativeSource>

</Binding>

    // Summary:

    //     Describes the location of the binding source relative to the position of

    //     the binding target.

    public enum RelativeSourceMode

    {

        // Summary:

        //     Allows you to bind the previous data item (not that control that contains

        //     the data item) in the list of data items being displayed.

        PreviousData = ,

        //

        // Summary:

        //     Refers to the element to which the template (in which the data-bound element

        //     exists) is applied. This is similar to setting a System.Windows.TemplateBindingExtension

        //     and is only applicable if the System.Windows.Data.Binding is within a template.

        TemplatedParent = ,

        //

        // Summary:

        //     Refers to the element on which you are setting the binding and allows you

        //     to bind one property of that element to another property on the same element.

        Self = ,

        //

        // Summary:

        //     Refers to the ancestor in the parent chain of the data-bound element. You

        //     can use this to bind to an ancestor of a specific type or its subclasses.

        //     This is the mode you use if you want to specify System.Windows.Data.RelativeSource.AncestorType

        //     and/or System.Windows.Data.RelativeSource.AncestorLevel.

        FindAncestor = ,

    }

     <Window.Resources>

        <ControlTemplate x:Key="template">

            <Canvas>

                <Canvas.RenderTransform>

                    <RotateTransform Angle="20"/>

                </Canvas.RenderTransform>

                <Ellipse Height="100" Width="150" Fill="{Binding RelativeSource={RelativeSource TemplatedParent},Path=Background}"></Ellipse>

                <ContentPresenter Margin="35" Content="{Binding RelativeSource={RelativeSource TemplatedParent},Path=Content}"/>

            </Canvas>

        </ControlTemplate>

    </Window.Resources>

    <StackPanel>

        <TextBlock>

               <TextBlock.Text>

                <Binding Path="Title">

                    <Binding.RelativeSource>

                      <RelativeSource Mode="FindAncestor" AncestorType="{x:Type Window}" />

                    </Binding.RelativeSource>

                </Binding>

               </TextBlock.Text>

        </TextBlock>

        <TextBlock Text="{Binding Path=Title,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}} }"></TextBlock>


        <Button Template="{StaticResource template}" Background="AliceBlue">

            <TextBlock FontSize="22">Click me</TextBlock>

        </Button>

    </StackPanel>

using System;

using System.ComponentModel;

using System.Windows.Markup;

namespace System.Windows.Data

{

    public class RelativeSource : MarkupExtension, ISupportInitialize

    {

        public RelativeSource();

        public RelativeSource(RelativeSourceMode mode);

        public RelativeSource(RelativeSourceMode mode, Type ancestorType, int ancestorLevel);

        public Type AncestorType { get; set; }


        public RelativeSourceMode Mode { get; set; }

        public static RelativeSource PreviousData { get; }

        public static RelativeSource Self { get; }

        public static RelativeSource TemplatedParent { get; }

        public override object ProvideValue(IServiceProvider serviceProvider);

        ...

    }

}

using System;

using System.ComponentModel;

using System.Windows.Markup;


namespace System.Windows.Data

{

    /// <summary>Implements a markup extension that describes the location of the binding source relative to the position of the binding target.</summary>

    [MarkupExtensionReturnType(typeof(RelativeSource))]

    public class RelativeSource : MarkupExtension, ISupportInitialize

    {

        private RelativeSourceMode _mode;

        private Type _ancestorType;

        private int _ancestorLevel = -;

        private static RelativeSource s_previousData;

        private static RelativeSource s_templatedParent;

        private static RelativeSource s_self;

        /// <summary>Gets a static value that is used to return a <see cref="T:System.Windows.Data.RelativeSource" /> constructed for the <see cref="F:System.Windows.Data.RelativeSourceMode.PreviousData" /> mode.</summary>

        /// <returns>A static <see cref="T:System.Windows.Data.RelativeSource" />.</returns>

        public static RelativeSource PreviousData

        {

            get

            {

                if (RelativeSource.s_previousData == null)

                {

                    RelativeSource.s_previousData = new RelativeSource(RelativeSourceMode.PreviousData);

                }

                return RelativeSource.s_previousData;

            }

        }

        /// <summary>Gets a static value that is used to return a <see cref="T:System.Windows.Data.RelativeSource" /> constructed for the <see cref="F:System.Windows.Data.RelativeSourceMode.TemplatedParent" /> mode.</summary>

        /// <returns>A static <see cref="T:System.Windows.Data.RelativeSource" />.</returns>

        public static RelativeSource TemplatedParent

        {

            get

            {

                if (RelativeSource.s_templatedParent == null)

                {

                    RelativeSource.s_templatedParent = new RelativeSource(RelativeSourceMode.TemplatedParent);

                }

                return RelativeSource.s_templatedParent;

            }

        }

        /// <summary>Gets a static value that is used to return a <see cref="T:System.Windows.Data.RelativeSource" /> constructed for the <see cref="F:System.Windows.Data.RelativeSourceMode.Self" /> mode.</summary>

        /// <returns>A static <see cref="T:System.Windows.Data.RelativeSource" />.</returns>

        public static RelativeSource Self

        {

            get

            {

                if (RelativeSource.s_self == null)

                {

                    RelativeSource.s_self = new RelativeSource(RelativeSourceMode.Self);

                }

                return RelativeSource.s_self;

            }

        }

        /// <summary>Gets or sets a <see cref="T:System.Windows.Data.RelativeSourceMode" /> value that describes the location of the binding source relative to the position of the binding target.</summary>

        /// <returns>One of the <see cref="T:System.Windows.Data.RelativeSourceMode" /> values. The default value is null.</returns>

        /// <exception cref="T:System.InvalidOperationException">This property is immutable after initialization. Instead of changing the <see cref="P:System.Windows.Data.RelativeSource.Mode" /> on this instance, create a new <see cref="T:System.Windows.Data.RelativeSource" /> or use a different static instance.</exception>

        [ConstructorArgument("mode")]

        public RelativeSourceMode Mode

        {

get

            {

                return this._mode;

            }

            set

            {

                if (this.IsUninitialized)

                {

                    this.InitializeMode(value);

                    return;

                }

                if (value != this._mode)

                {

                    throw new InvalidOperationException(SR.Get("RelativeSourceModeIsImmutable"));

                }

            }

        }

        /// <summary>Gets or sets the type of ancestor to look for.</summary>

        /// <returns>The type of ancestor. The default value is null.</returns>

        /// <exception cref="T:System.InvalidOperationException">The <see cref="T:System.Windows.Data.RelativeSource" /> is not in the <see cref="F:System.Windows.Data.RelativeSourceMode.FindAncestor" /> mode.</exception>

        public Type AncestorType

        {

get

            {

                return this._ancestorType;

            }

            set

            {

                if (this.IsUninitialized)

                {

                    this.AncestorLevel = ;

                }

                if (this._mode != RelativeSourceMode.FindAncestor)

                {

                    if (value != null)

                    {

                        throw new InvalidOperationException(SR.Get("RelativeSourceNotInFindAncestorMode"));

                    }

                }

                else

                {

                    this._ancestorType = value;

                }

            }

        }

        /// <summary>Gets or sets the level of ancestor to look for, in <see cref="F:System.Windows.Data.RelativeSourceMode.FindAncestor" /> mode. Use 1 to indicate the one nearest to the binding target element.</summary>

        /// <returns>The ancestor level. Use 1 to indicate the one nearest to the binding target element.</returns>

        public int AncestorLevel

        {

get

            {

                return this._ancestorLevel;

            }

            set

            {

                if (this._mode != RelativeSourceMode.FindAncestor)

                {

                    if (value != )

                    {

                        throw new InvalidOperationException(SR.Get("RelativeSourceNotInFindAncestorMode"));

                    }

                }

                else

                {

                    if (value < )

                    {

                        throw new ArgumentOutOfRangeException(SR.Get("RelativeSourceInvalidAncestorLevel"));

                    }

                    this._ancestorLevel = value;

                }

            }

        }

        private bool IsUninitialized

        {

            get

            {

                return this._ancestorLevel == -;

            }

        }

        /// <summary>Initializes a new instance of the <see cref="T:System.Windows.Data.RelativeSource" /> class.</summary>

        public RelativeSource()

        {

            this._mode = RelativeSourceMode.FindAncestor;

        }

        /// <summary>Initializes a new instance of the <see cref="T:System.Windows.Data.RelativeSource" /> class with an initial mode.</summary>

        /// <param name="mode">One of the <see cref="T:System.Windows.Data.RelativeSourceMode" /> values.</param>

        public RelativeSource(RelativeSourceMode mode)

        {

            this.InitializeMode(mode);

        }

        /// <summary>Initializes a new instance of the <see cref="T:System.Windows.Data.RelativeSource" /> class with an initial mode and additional tree-walking qualifiers for finding the desired relative source.</summary>

        /// <param name="mode">One of the <see cref="T:System.Windows.Data.RelativeSourceMode" /> values. For this signature to be relevant, this should be <see cref="F:System.Windows.Data.RelativeSourceMode.FindAncestor" />.</param>

        /// <param name="ancestorType">The <see cref="T:System.Type" /> of ancestor to look for.</param>

        /// <param name="ancestorLevel">The ordinal position of the desired ancestor among all ancestors of the given type. </param>

        public RelativeSource(RelativeSourceMode mode, Type ancestorType, int ancestorLevel)

        {

            this.InitializeMode(mode);

            this.AncestorType = ancestorType;

            this.AncestorLevel = ancestorLevel;

        }

        /// <summary>This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code.</summary>

        void ISupportInitialize.BeginInit()

        {

        }


        ///<summary>This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code.</summary>

        void ISupportInitialize.EndInit()

        {

            if (this.IsUninitialized)

            {

                throw new InvalidOperationException(SR.Get("RelativeSourceNeedsMode"));

            }

            if (this._mode == RelativeSourceMode.FindAncestor && this.AncestorType == null)

            {

                throw new InvalidOperationException(SR.Get("RelativeSourceNeedsAncestorType"));

            }

        }


        /// <summary>Indicates whether the <see cref="P:System.Windows.Data.RelativeSource.AncestorType" /> property should be persisted.</summary>

        /// <returns>true if the property value has changed from its default; otherwise, false.</returns>

public bool ShouldSerializeAncestorType()

        {

            return this._mode == RelativeSourceMode.FindAncestor;

        }


        /// <summary>Indicates whether the <see cref="P:System.Windows.Data.RelativeSource.AncestorLevel" /> property should be persisted.</summary>

        /// <returns>true if the property value has changed from its default; otherwise, false.</returns>

public bool ShouldSerializeAncestorLevel()

        {

            return this._mode == RelativeSourceMode.FindAncestor;

        }


        /// <summary>Returns an object that should be set as the value on the target object's property for this markup extension. For <see cref="T:System.Windows.Data.RelativeSource" />, this is another <see cref="T:System.Windows.Data.RelativeSource" />, using the appropriate source for the specified mode. </summary>

        /// <returns>Another <see cref="T:System.Windows.Data.RelativeSource" />.</returns>

        /// <param name="serviceProvider">An object that can provide services for the markup extension. In this implementation, this parameter can be null.</param>

        public override object ProvideValue(IServiceProvider serviceProvider)

        {

            if (this._mode == RelativeSourceMode.PreviousData)

            {

                return RelativeSource.PreviousData;

            }

            if (this._mode == RelativeSourceMode.Self)

            {

                return RelativeSource.Self;

            }

            if (this._mode == RelativeSourceMode.TemplatedParent)

            {

                return RelativeSource.TemplatedParent;

            }

            return this;

        }

        private void InitializeMode(RelativeSourceMode mode)

        {

            if (mode == RelativeSourceMode.FindAncestor)

            {

                this._ancestorLevel = ;

                this._mode = mode;

                return;

            }

            if (mode == RelativeSourceMode.PreviousData || mode == RelativeSourceMode.Self || mode == RelativeSourceMode.TemplatedParent)

            {

                this._ancestorLevel = ;

                this._mode = mode;

                return;

            }

            throw new ArgumentException(SR.Get("RelativeSourceModeInvalid"), "mode");

        }

    }

}