Server-side Programming Overview

You can configure the settings of RadMultiSelect and create its elements in the code-behind via the Server-Side API of the control.

RadMultiSelect Server-side Events

Below you can see a list of the server-side events available in the RadMultiSelect:

• OnDataBinding
• OnDataBound
• OnInit
• OnItemDataBound
• OnLoad
• OnPreRender
• OnItemSelected
• OnItemDeselected
• OnSelectionChanged

RadMultiSelect Public Properties and Methods

For a list with the server-side properties and methods of the control, see the Server-Side API of the RadMultiSelect class. You can also find it in the intellisense in Visual Studio.

Get Selected Items Text and Value

RadMultiSelect exposes the Text and Value server-side properties that contain the information from the DataTextField and DataValueField fields respectively.

Example 1: Get selected items value and text from RadMultiSelect

<telerik:RadMultiSelect ID="RadMultiSelect1" runat="server" Filter="Contains" Width="400px" Placeholder="Select items...">
</telerik:RadMultiSelect>

<asp:Button ID="Button1" runat="server" Text="Get Data" OnClick="Button1_Click" />

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        RadMultiSelect1.DataTextField = "textField";
        RadMultiSelect1.DataValueField = "valueField";
        RadMultiSelect1.DataSource = GetData();
        RadMultiSelect1.DataBind();
    }
}

private object GetData()
{
    DataTable dt = new DataTable();
    dt.Columns.Add("textField");
    dt.Columns.Add("valueField");

    for (int i = 0; i < 10; i++)
    {
        dt.Rows.Add("Item " + i, i);
    }

    return dt;
}

protected void Button1_Click(object sender, EventArgs e)
{
    var selectedValues = RadMultiSelect1.Value;

    foreach (string value in selectedValues)
    {
        MultiSelectItem selectedItem = RadMultiSelect1.Items.FindChildByValue(value);
        string result = string.Format("Selected item with text: <strong>{0}</strong> and value: <strong>{1}</strong><br />", selectedItem.Text, selectedItem.Value);
        Response.Write(result);
    }
}

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    If Not IsPostBack Then
        RadMultiSelect1.DataTextField = "textField"
        RadMultiSelect1.DataValueField = "valueField"
        RadMultiSelect1.DataSource = GetData()
        RadMultiSelect1.DataBind()
    End If
End Sub

Private Function GetData() As Object
    Dim dt As DataTable = New DataTable()
    dt.Columns.Add("textField")
    dt.Columns.Add("valueField")

    For i As Integer = 0 To 10 - 1
        dt.Rows.Add("Item " & i, i)
    Next

    Return dt
End Function

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim selectedValues = RadMultiSelect1.Value

    For Each value As String In selectedValues
        Dim selectedItem As MultiSelectItem = RadMultiSelect1.Items.FindChildByValue(value)
        Dim result As String = String.Format("Selected item with text: <strong>{0}</strong> and value: <strong>{1}</strong><br />", selectedItem.Text, selectedItem.Value)
        Response.Write(result)
    Next
End Sub