Data binding

Data binding is a mechanism for automatic population of the RadDropDownList with items, based on the provided data structure. Three properties control the data binding:

  • DataSource - specifies the data structure to be bound.

  • DisplayMember - specifies the particular field in the data source which will be used from the items in RadDropDownList for their Text.

  • ValueMember - specifies the particular field in the data source which will be stored in the items Value property.

RadDropDownList supports data binding either at design time or at run time:

Data binding at design time

You can set the DataSource property at design time in the Properties window of Visual Studio.

  1. Select the DataSource property and click the drop-down arrow to display all existing data sources on the form.

  2. Click the Add Project Data Sourceā€¦ link and follow the instructions in the Data Source Configuration Wizard to add a data source to your project. You can use a single database table.

    Figure: 1 Setting the DataSource at Design time

    dropdown-and-listcontrol-dropdownlist-populating-with-data-data-binding 001

  3. Afterwards, you need to specify the DisplayMember and ValueMember properties.

    Figure: 2 Setting the DisplayMember and ValueMember properties at Design time

    dropdown-and-listcontrol-dropdownlist-populating-with-data-data-binding 002

    Figure: 3 RadDropDownList bound at Design time

    dropdown-and-listcontrol-dropdownlist-populating-with-data-data-binding 003

Data binding at run time

You can bind RadDropDownList programmatically as well. The following code snippet demonstrates how to bind it to a collection of custom objects:

Data binding at run time

public class Item
    public int Id { get; set; }

    public string Description { get; set; }

    public Item(int id, string description)
        this.Id = id;
        this.Description = description;

public void Bind()
    List<Item> items = new List<Item>();
    for (int i = 0; i < 10; i++)
        items.Add(new Item(i,"Data" + i));
    this.radDropDownList1.DataSource = items;
    this.radDropDownList1.DisplayMember = "Description";
    this.radDropDownList1.ValueMember = "Id";

Public Class Item
    Public Property Id() As Integer
            Return m_Id
        End Get
        Set(value As Integer)
            m_Id = value
        End Set
    End Property
    Private m_Id As Integer
    Public Property Description() As String
            Return m_Description
        End Get
        Set(value As String)
            m_Description = value
        End Set
    End Property
    Private m_Description As String
    Public Sub New(id As Integer, description As String)
        Me.Id = id
        Me.Description = description
    End Sub
End Class
Public Sub Bind()
    Dim items As New List(Of Item)()
    For i As Integer = 0 To 9
        items.Add(New Item(i, "Data" + i))
    Me.radDropDownList1.DataSource = items
    Me.radDropDownList1.DisplayMember = "Description"
    Me.radDropDownList1.ValueMember = "Id"
End Sub

Figure: 4 RadDropDownList bound at Run time

dropdown-and-listcontrol-dropdownlist-populating-with-data-data-binding 004

See Also

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