---
title: Customize Item Addition with BindingSource component
ms.date: "03/30/2017"
dev_langs: 
  - "csharp"
  - "vb"
  - "cpp"
helpviewer_keywords: 
  - "controls [Windows Forms], creating new items"
  - "BindingSource component [Windows Forms], customizing item addition with"
  - "examples [Windows Forms], BindingSource component"
  - "BindingSource component [Windows Forms], examples"
ms.assetid: 1aae11fc-6fb2-4cb9-b3d0-e0638fe77ef0
---
# How to: Customize Item Addition with the Windows Forms BindingSource
When you use a <xref:System.Windows.Forms.BindingSource> component to bind a Windows Forms control to a data source, you may find it necessary to customize the creation of new items. The <xref:System.Windows.Forms.BindingSource> component makes this straightforward by providing the <xref:System.Windows.Forms.BindingSource.AddingNew> event, which is typically raised when the bound control needs to create a new item. Your event handler can provide whatever custom behavior is required (for example, calling a method on a Web service or getting a new object from a class factory).  
  
> [!NOTE]
> When an item is added by handling the <xref:System.Windows.Forms.BindingSource.AddingNew> event, the addition cannot be canceled.  
  
## Example  
 The following example demonstrates how to bind a <xref:System.Windows.Forms.DataGridView> control to a class factory by using a <xref:System.Windows.Forms.BindingSource> component. When the user clicks the <xref:System.Windows.Forms.DataGridView> control's new row, the <xref:System.Windows.Forms.BindingSource.AddingNew> event is raised. The event handler creates a new `DemoCustomer` object, which is assigned to the <xref:System.ComponentModel.AddingNewEventArgs.NewObject%2A?displayProperty=nameWithType> property. This causes the new `DemoCustomer` object to be added to the <xref:System.Windows.Forms.BindingSource> component's list and to be displayed in the new row of the <xref:System.Windows.Forms.DataGridView> control.  
  
 [!code-cpp[System.Windows.Forms.DataConnector.AddingNew#1](~/samples/snippets/cpp/VS_Snippets_Winforms/System.Windows.Forms.DataConnector.AddingNew/CPP/form1.cpp#1)]
 [!code-csharp[System.Windows.Forms.DataConnector.AddingNew#1](~/samples/snippets/csharp/VS_Snippets_Winforms/System.Windows.Forms.DataConnector.AddingNew/CS/form1.cs#1)]
 [!code-vb[System.Windows.Forms.DataConnector.AddingNew#1](~/samples/snippets/visualbasic/VS_Snippets_Winforms/System.Windows.Forms.DataConnector.AddingNew/VB/form1.vb#1)]  
  
## Compiling the Code  
 This example requires:  
  
- References to the System, System.Data, System.Drawing and System.Windows.Forms assemblies.  
  
## See also

- <xref:System.Windows.Forms.BindingNavigator>
- <xref:System.Windows.Forms.DataGridView>
- <xref:System.Windows.Forms.BindingSource>
- [BindingSource Component](bindingsource-component.md)
- [How to: Bind a Windows Forms Control to a Type](how-to-bind-a-windows-forms-control-to-a-type.md)