Home / Community & Support / Knowledge Base / RadControls for WinForms / General and Installation / Binding two controls to one and the same data source

Binding two controls to one and the same data source

Article Info

Rating: Not rated

Article information

Article relates to

RadControls for WinForms 

Created by

Nikolay Diyanov

Last modified

Apr 10, 2012

Last modified by

Nikolay Diyanov

PROBLEM

You have two RadDropDownLists and you bind them to one and the same data source (let's assume that this is a DataTable). When you select an item from the first RadDropDownList, the second RadDropDownList also selects the same item, but this is not the desired behavior.

SOLUTION

This is the normal behavior of how data-binding works in Windows Forms. When you bind a control to a data source, the control needs a binding source to be able to synchronize the selection and changes to its data source. When you do not explicitly set a binding source, the control used the form's binding source. Since both controls are bound to the same
collection, the form assigns the same binding source to both controls and when the binding source synchronizes the selection, it pushes the second RadDropDownList to change its selection. In order to use one source with two controls, you have to assign different binding sources. Here is a code snippet which demonstrates how to achieve this:

C#
BindingSource source1 = new BindingSource();
source1.DataSource = nwindDataSet.Employees;
BindingSource source2 = new BindingSource();
source2.DataSource = nwindDataSet.Employees;
 
this.radDropDownList1.DisplayMember = "FirstName";
this.radDropDownList1.ValueMember = "EmployeeID";
this.radDropDownList1.DataSource = source1;
 
this.radDropDownList2.DisplayMember = "FirstName";
this.radDropDownList2.ValueMember = "EmployeeID";
this.radDropDownList2.DataSource = source2;

VB.NET
Dim source1 As New BindingSource()
source1.DataSource = nwindDataSet.Employees
Dim source2 As New BindingSource()
source2.DataSource = nwindDataSet.Employees
 
Me.radDropDownList1.DisplayMember = "FirstName"
Me.radDropDownList1.ValueMember = "EmployeeID"
Me.radDropDownList1.DataSource = source1
 
Me.radDropDownList2.DisplayMember = "FirstName"
Me.radDropDownList2.ValueMember = "EmployeeID"
Me.radDropDownList2.DataSource = source2

Comments

There are no comments yet.
If you'd like to comment on this KB article, please, send us a Support Ticket.
Thank you!

Please Sign In to rate this article.