---
title: "How to: Specify a Custom Popup Position"
ms.date: "03/30/2017"
dev_langs: 
  - "csharp"
  - "vb"
helpviewer_keywords: 
  - "Popup control [WPF], specifying custom position"
ms.assetid: 28c24f39-d3aa-4ee2-b950-384b4a5dab92
---
# How to: Specify a Custom Popup Position
This example shows how to specify a custom position for a <xref:System.Windows.Controls.Primitives.Popup> control when the <xref:System.Windows.Controls.Primitives.Popup.Placement%2A> property is set to <xref:System.Windows.Controls.Primitives.PlacementMode.Custom>.  
  
## Example  
 When the <xref:System.Windows.Controls.Primitives.Popup.Placement%2A> property is set to <xref:System.Windows.Controls.Primitives.PlacementMode.Custom>, the <xref:System.Windows.Controls.Primitives.Popup> calls a defined instance of the <xref:System.Windows.Controls.Primitives.CustomPopupPlacementCallback> delegate. This delegate returns a set of possible points that are relative to the top-left corner of the target area and the top-left corner of the <xref:System.Windows.Controls.Primitives.Popup>. The <xref:System.Windows.Controls.Primitives.Popup> placement occurs at the point that provides the best visibility.  
  
 The following example shows how to define the position of a <xref:System.Windows.Controls.Primitives.Popup> by setting the <xref:System.Windows.Controls.Primitives.Popup.Placement%2A> property to <xref:System.Windows.Controls.Primitives.PlacementMode.Custom>. It also shows how to create and assign a <xref:System.Windows.Controls.Primitives.CustomPopupPlacementCallback> delegate in order to position the <xref:System.Windows.Controls.Primitives.Popup>.  The callback delegate returns two <xref:System.Windows.Controls.Primitives.CustomPopupPlacement> objects.  If the <xref:System.Windows.Controls.Primitives.Popup> is hidden by a screen edge at the first position, the <xref:System.Windows.Controls.Primitives.Popup> is placed at the second position.  
  
 [!code-xaml[PopupCustomPlacement#CustomPlacement](~/samples/snippets/csharp/VS_Snippets_Wpf/PopupCustomPlacement/CSharp/Window1.xaml#customplacement)]  
  
 [!code-csharp[PopupCustomPlacement#DelegateInstance](~/samples/snippets/csharp/VS_Snippets_Wpf/PopupCustomPlacement/CSharp/Window1.xaml.cs#delegateinstance)]
 [!code-vb[PopupCustomPlacement#DelegateInstance](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PopupCustomPlacement/visualbasic/window1.xaml.vb#delegateinstance)]  
  
 [!code-csharp[PopupCustomPlacement#DelegateDefinition](~/samples/snippets/csharp/VS_Snippets_Wpf/PopupCustomPlacement/CSharp/Window1.xaml.cs#delegatedefinition)]
 [!code-vb[PopupCustomPlacement#DelegateDefinition](~/samples/snippets/visualbasic/VS_Snippets_Wpf/PopupCustomPlacement/visualbasic/window1.xaml.vb#delegatedefinition)]  
  
 For the complete sample, see [Popup Placement Sample](https://github.com/dotnet/docs-desktop/tree/main/dotnet-desktop-guide/samples/snippets/csharp/VS_Snippets_Wpf/PopupPositionSnippet/CS).  
  
## See also

- <xref:System.Windows.Controls.Primitives.Popup>
- [Popup overview](popup-overview.md)
- [How-to articles](popup-how-to-topics.md)