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Working with Items at Server-Side

Using the server-side API, you can programmatically add, remove, disable, or select items in RadComboBox.

Adding items

Use the Add method of the RadComboBoxItemCollection object to add items programmatically at Page_Load, Button_Click or another server event handler:


protected void Page_Load(object sender, EventArgs e)
{  
    if (!Page.IsPostBack)  
    {    
        RadComboBoxItem item1 = new RadComboBoxItem();    
        item1.Text = "Item1";   
        item1.Value = "1";    
        RadComboBox1.Items.Add(item1);    
        RadComboBoxItem item2 = new RadComboBoxItem();   
        item2.Text = "Item2";    
        item2.Value = "2";   
        RadComboBox1.Items.Add(item2);    
        RadComboBoxItem item3 = new RadComboBoxItem();    
        item3.Text = "Item3";   
        item3.Value = "3";   
        RadComboBox1.Items.Add(item3);  
    }
}


Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load

    If Not Page.IsPostBack Then
        Dim item1 As New RadComboBoxItem()
        item1.Text = "Item1"
        item1.Value = "1"
        RadComboBox1.Items.Add(item1)
        Dim item2 As New RadComboBoxItem()
        item2.Text = "Item2"
        item2.Value = "2"
        RadComboBox1.Items.Add(item2)
        Dim item3 As New RadComboBoxItem()
        item3.Text = "Item3"
        item3.Value = "3"
        RadComboBox1.Items.Add(item3)
    End If
End Sub 'Page_Load

Removing items

Use the Remove method of the RadComboBoxItemCollection object to remove items:


//Find the desired item and remove it.
RadComboBoxItem item = RadComboBox1.FindItemByText("Item1");
item.Remove();

//Remove an item from the Items collection. The code line below removes the first item. Its index is 0.
RadComboBox1.Items.Remove(0);



'Find the desired item and remove it.
Dim item As RadComboBoxItem = RadComboBox1.FindItemByText("Item1")
item.Remove()

'Remove an item from the Items collection. The code line below removes the first item. Its index is 0.
RadComboBox1.Items.Remove(0)

Disabling items

Use the Enable property of the RadComboBoxItem object to enable or disable an item:


//Find the desired item and disable it.
RadComboBoxItem item = RadComboBox1.FindItemByText("Item1");
item.Enabled = false;


'Find the item and disable it.
Dim item As RadComboBoxItem = RadComboBox1.FindItemByText("Item1")
item.Enabled = False

Selecting Items

Use the Selected property of an item to select it, or use the SelectedIndex property of RadComboBox:



//Use RadComboBoxItem.Selected
RadComboBoxItem item = RadComboBox1.FindItemByText("Item 2");
item.Selected = true;

//Use RadComboBox.SelectedIndex
int index = RadComboBox1.FindItemIndexByValue("2");
RadComboBox1.SelectedIndex = index;

//You can also use the SelectedValue property.
RadComboBox1.SelectedValue = value;



'Use RadComboBoxItem.Selected
Dim item As RadComboBoxItem = RadComboBox1.FindItemByText("Item 2")
item.Selected = True

'Use RadComboBox.SelectedIndex
Dim index As Integer = RadComboBox1.FindItemIndexByValue("2")
RadComboBox1.SelectedIndex = index

'You can also use the SelectedValue property.
RadComboBox1.SelectedValue = value

Finding Items

You can locate by searching on the Text or Value properties. You can retrieve either the index of the item or a reference to the item itself. Use the RadComboBox methods:

  • FindItemByText

  • FindItemByValue

  • FindItemIndexByText

  • FindItemIndexByValue



using System;
using Telerik.Web.UI;

namespace RadWindow
{    
    public partial class _Default : System.Web.UI.Page    
    {        
        protected void Page_Load(object sender, EventArgs e)        
        {            
            RadComboBox1.Items.Add(new RadComboBoxItem("One", "1"));            
            RadComboBox1.Items.Add(new RadComboBoxItem("Two", "2"));           
            RadComboBox1.Items.Add(new RadComboBoxItem("Three", "3"));        
        }
        protected void Button1_Click(object sender, EventArgs e)        
        {            
            RadComboBoxItem item = null;            
            int index = -1;
            //Get a reference to a RadComboBoxItem with Text property = "Two".            
            item = RadComboBox1.FindItemByText("Two");

            //Get a reference to a RadComboBoxItem with Value property = "2".            
            item = RadComboBox1.FindItemByValue("2");

            //Get the index of a RadComboBoxItem with Text property = "Two".            
            index = RadComboBox1.FindItemIndexByText("Two");            
            item = RadComboBox1.Items[index];

            //Get the index of a RadComboBoxItem with Value property = "2".            
            index = RadComboBox1.FindItemIndexByValue("2");            
            item = RadComboBox1.Items[index];        
        }    
    }
}



Imports System
Imports Telerik.Web.UI

namespace RadWindow 

    Public Partial Class _Default  Inherits System.Web.UI.Page  
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
            RadComboBox1.Items.Add(New RadComboBoxItem("One", "1"))
            RadComboBox1.Items.Add(New RadComboBoxItem("Two", "2"))
            RadComboBox1.Items.Add(New RadComboBoxItem("Three", "3"))
        End Sub
        Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
            Dim item As RadComboBoxItem = Nothing
            Dim index As Integer = -1
            'Get a reference to a RadComboBoxItem with Text property = "Two".   
            item = RadComboBox1.FindItemByText("Two")

            'Get a reference to a RadComboBoxItem with Value property = "2".   
            item = RadComboBox1.FindItemByValue("2")

            'Get the index of a RadComboBoxItem with Text property = "Two".  
            index = RadComboBox1.FindItemIndexByText("Two")
            item = RadComboBox1.Items(index)

            'Get the index of a RadComboBoxItem with Value property = "2".   
            index = RadComboBox1.FindItemIndexByValue("2")
            item = RadComboBox1.Items(index)
        End Sub
    End Class
End Namespace

For a live example, see: Add/Remove/Disable Items

See Also

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