docs-desktop/dotnet-desktop-guide/framework/wpf/advanced/walkthrough-mapping-properties-using-the-elementhost-control.md

---
title: "Walkthrough: Mapping Properties Using the ElementHost Control"
ms.date: 08/18/2018
dev_langs:
  - "csharp"
  - "vb"
helpviewer_keywords:
  - "mapping properties [WPF]"
  - "ElementHost control [WPF], mapping properties"
ms.assetid: bccd6e0d-2272-4924-9107-ff8ed58b88aa
---
# Walkthrough: Mapping Properties Using the ElementHost Control

This walkthrough shows you how to use the <xref:System.Windows.Forms.Integration.ElementHost.PropertyMap%2A> property to map Windows Forms properties to corresponding properties on a hosted WPF element.

Tasks illustrated in this walkthrough include:

- Creating the project.

- Defining a new property mapping.

- Removing a default property mapping.

- Extending a default property mapping.

When you are finished, you will be able to map Windows Forms properties to corresponding WPF properties on a hosted element.

## Prerequisites

You need the following components to complete this walkthrough:

- Visual Studio 2017

## Creating the Project

### To create the project

1. Create a **Windows Forms App** project named `PropertyMappingWithElementHost`.

2. In **Solution Explorer**, add references to the following WPF assemblies.

    - PresentationCore

    - PresentationFramework

    - WindowsBase

    - WindowsFormsIntegration

3. Copy the following code into the top of the `Form1` code file.

     [!code-csharp[PropertyMappingWithElementHost#10](~/samples/snippets/csharp/VS_Snippets_Wpf/PropertyMappingWithElementHost/CSharp/PropertyMappingWithElementHost/Form1.cs#10)]
     [!code-vb[PropertyMappingWithElementHost#10](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PropertyMappingWithElementHost/VisualBasic/PropertyMappingWithElementHost/Form1.vb#10)]

4. Open `Form1` in the Windows Forms Designer. Double-click the form to add an event handler for the <xref:System.Windows.Forms.Form.Load> event.

5. Return to the Windows Forms Designer and add an event handler for the form's <xref:System.Windows.Forms.Control.Resize> event. For more information, see [How to: Create Event Handlers Using the Designer](/previous-versions/visualstudio/visual-studio-2010/zwwsdtbk(v=vs.100)).

6. Declare an <xref:System.Windows.Forms.Integration.ElementHost> field in the `Form1` class.

     [!code-csharp[PropertyMappingWithElementHost#16](~/samples/snippets/csharp/VS_Snippets_Wpf/PropertyMappingWithElementHost/CSharp/PropertyMappingWithElementHost/Form1.cs#16)]
     [!code-vb[PropertyMappingWithElementHost#16](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PropertyMappingWithElementHost/VisualBasic/PropertyMappingWithElementHost/Form1.vb#16)]

## Defining New Property Mappings

The <xref:System.Windows.Forms.Integration.ElementHost> control provides several default property mappings. You add a new property mapping by calling the <xref:System.Windows.Forms.Integration.PropertyMap.Add%2A> method on the <xref:System.Windows.Forms.Integration.ElementHost> control's <xref:System.Windows.Forms.Integration.ElementHost.PropertyMap%2A>.

### To define new property mappings

1. Copy the following code into the definition for the `Form1` class.

     [!code-csharp[PropertyMappingWithElementHost#12](~/samples/snippets/csharp/VS_Snippets_Wpf/PropertyMappingWithElementHost/CSharp/PropertyMappingWithElementHost/Form1.cs#12)]
     [!code-vb[PropertyMappingWithElementHost#12](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PropertyMappingWithElementHost/VisualBasic/PropertyMappingWithElementHost/Form1.vb#12)]

     The `AddMarginMapping` method adds a new mapping for the <xref:System.Windows.Forms.Control.Margin%2A> property.

     The `OnMarginChange` method translates the <xref:System.Windows.Forms.Control.Margin%2A> property to the WPF <xref:System.Windows.FrameworkElement.Margin%2A> property.

2. Copy the following code into the definition for the `Form1` class.

     [!code-csharp[PropertyMappingWithElementHost#14](~/samples/snippets/csharp/VS_Snippets_Wpf/PropertyMappingWithElementHost/CSharp/PropertyMappingWithElementHost/Form1.cs#14)]
     [!code-vb[PropertyMappingWithElementHost#14](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PropertyMappingWithElementHost/VisualBasic/PropertyMappingWithElementHost/Form1.vb#14)]

     The `AddRegionMapping` method adds a new mapping for the <xref:System.Windows.Forms.Control.Region%2A> property.

     The `OnRegionChange` method translates the <xref:System.Windows.Forms.Control.Region%2A> property to the WPF <xref:System.Windows.UIElement.Clip%2A> property.

     The `Form1_Resize` method handles the form's <xref:System.Windows.Forms.Control.Resize> event and sizes the clipping region to fit the hosted element.

## Removing a Default Property Mapping

Remove a default property mapping by calling the <xref:System.Windows.Forms.Integration.PropertyMap.Remove%2A> method on the <xref:System.Windows.Forms.Integration.ElementHost> control's <xref:System.Windows.Forms.Integration.ElementHost.PropertyMap%2A>.

### To remove a default property mapping

- Copy the following code into the definition for the `Form1` class.

     [!code-csharp[PropertyMappingWithElementHost#13](~/samples/snippets/csharp/VS_Snippets_Wpf/PropertyMappingWithElementHost/CSharp/PropertyMappingWithElementHost/Form1.cs#13)]
     [!code-vb[PropertyMappingWithElementHost#13](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PropertyMappingWithElementHost/VisualBasic/PropertyMappingWithElementHost/Form1.vb#13)]

     The `RemoveCursorMapping` method deletes the default mapping for the <xref:System.Windows.Forms.Control.Cursor%2A> property.

## Extending a Default Property Mapping

You can use a default property mapping and also extend it with your own mapping.

### To extend a default property mapping

- Copy the following code into the definition for the `Form1` class.

     [!code-csharp[PropertyMappingWithElementHost#15](~/samples/snippets/csharp/VS_Snippets_Wpf/PropertyMappingWithElementHost/CSharp/PropertyMappingWithElementHost/Form1.cs#15)]
     [!code-vb[PropertyMappingWithElementHost#15](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PropertyMappingWithElementHost/VisualBasic/PropertyMappingWithElementHost/Form1.vb#15)]

     The `ExtendBackColorMapping` method adds a custom property translator to the existing <xref:System.Windows.Forms.Control.BackColor%2A> property mapping.

     The `OnBackColorChange` method assigns a specific image to the hosted control's <xref:System.Windows.Controls.Control.Background%2A> property. The `OnBackColorChange` method is called after the default property mapping is applied.

## Initialize your property mappings

1. Copy the following code into the definition for the `Form1` class.

     [!code-csharp[PropertyMappingWithElementHost#11](~/samples/snippets/csharp/VS_Snippets_Wpf/PropertyMappingWithElementHost/CSharp/PropertyMappingWithElementHost/Form1.cs#11)]
     [!code-vb[PropertyMappingWithElementHost#11](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PropertyMappingWithElementHost/VisualBasic/PropertyMappingWithElementHost/Form1.vb#11)]

     The `Form1_Load` method handles the <xref:System.Windows.Forms.Form.Load> event and performs the following initialization.

    - Creates a WPF <xref:System.Windows.Controls.Button> element.

    - Calls the methods you defined earlier in the walkthrough to set up the property mappings.

    - Assigns initial values to the mapped properties.

2. Press F5 to build and run the application.

## See also

- <xref:System.Windows.Forms.Integration.ElementHost.PropertyMap%2A?displayProperty=nameWithType>
- <xref:System.Windows.Forms.Integration.WindowsFormsHost.PropertyMap%2A?displayProperty=nameWithType>
- <xref:System.Windows.Forms.Integration.WindowsFormsHost>
- [Windows Forms and WPF Property Mapping](windows-forms-and-wpf-property-mapping.md)
- [Design XAML in Visual Studio](/visualstudio/xaml-tools/designing-xaml-in-visual-studio)
- [Walkthrough: Hosting a WPF Composite Control in Windows Forms](walkthrough-hosting-a-wpf-composite-control-in-windows-forms.md)