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Working at Server-side

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

Adding items

Use the Add method of the RadListBoxItemCollection object to add items programmatically:

C#
protected void Page_Load(object sender, EventArgs e)
{
   if (!IsPostBack)
   {
	   RadListBoxItem item = new RadListBoxItem("Item 1", "1");
	   RadListBox1.Items.Add(item);
	   //copy the first item
	   RadListBoxItem item2 = item.Clone();
	   RadListBox1.Items.Add(item2);
	   //make the third item disabled
	   RadListBoxItem item3 = new RadListBoxItem();
	   item3.Text = "Item 3";
	   item3.Value = "3";
	   item3.Enabled = false;
	   RadListBox1.Items.Add(item3);
   }
} 		
VB.NET
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
	If Not IsPostBack Then
		Dim item As New RadListBoxItem("Item 1", "1")
		RadListBox1.Items.Add(item)
		'copy the first item
		Dim item2 As RadListBoxItem = item.Clone()
		RadListBox1.Items.Add(item2)
		'make the third item disabled
		Dim item3 As New RadListBoxItem()
		item3.Text = "Item 3"
		item3.Value = "3"
		item3.Enabled = False
		RadListBox1.Items.Add(item3)
	End If
End Sub

Removing items

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

C#
RadListBoxItem itemToRemove = RadListBox1.FindItemByText("Item 3");
RadListBox1.Items.Remove(itemToRemove);		
VB.NET
Dim itemToRemove As RadListBoxItem = RadListBox1.FindItemByText("Item 3")
RadListBox1.Items.Remove(itemToRemove) 	

Sorting items

Use the SortItems method of RadListBox object to sort items:

C#
RadListBox1.Sort = RadListBoxSort.Ascending;
RadListBox1.SortItems();
VB.NET
RadListBox1.Sort = RadListBoxSort.Ascending
RadListBox1.SortItems()

You can also use the Sort method of the RadListBoxItemCollection object to sort items:

C#
RadListBox1.Items.Sort();
VB.NET
RadListBox1.Items.Sort()	

You can pass an object of type IComparer as an argument of the function:

C#
protected void Button1_Click(object sender, EventArgs e)
{
	RadListBox1.Items.Sort(new CustomComparer());
}

public class CustomComparer : System.Collections.IComparer
{
	public CustomComparer() { }

	public int Compare(object x, object y)
	{
		RadListBoxItem ItemX = (RadListBoxItem)x;
		RadListBoxItem ItemY = (RadListBoxItem)y;

		return ItemX.Text.CompareTo(ItemY.Text);
	}
}	
VB.NET
	Protected Sub Button1_Click(sender As Object, e As EventArgs)
		RadListBox1.Items.Sort(New CustomComparer())
	End Sub

	Public Class CustomComparer
		Implements System.Collections.IComparer
		Public Sub New()
		End Sub

		Public Function Compare(x As Object, y As Object) As Integer
			Dim ItemX As RadListBoxItem = DirectCast(x, RadListBoxItem)
			Dim ItemY As RadListBoxItem = DirectCast(y, RadListBoxItem)

			Return ItemX.Text.CompareTo(ItemY.Text)
		End Function
	End Class

You can also use a lambda expression as an argument:

C#
	RadListBox1.Items.Sort(item => item.Text);	
VB.NET
	RadListBox1.Items.Sort(Function(item) item.Text)	

Disabling items

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

C#
	RadListBoxItem itemToDisable = RadListBox1.FindItemByText("Item 3");
	itemToDisable.Enabled = false;
	RadListBox1.Items[0].Enabled = false;
VB.NET
	Dim itemToDisable As RadListBoxItem = RadListBox1.FindItemByText("Item 3")
	itemToDisable.Enabled = False
	RadListBox1.Items(0).Enabled = False 

Use the Selected property of an item to select it, or use the SelectedIndex property of RadListBox. Note that to select multiple items you need to set the SelectionMode="Multiple" property.

C#
	RadListBoxItem itemToSelect = RadListBox1.FindItemByText("Item 3");
	itemToSelect.Selected = true;
	RadListBox1.Items[0].Selected = true;
VB.NET
	Dim itemToSelect As RadListBoxItem = RadListBox1.FindItemByText("Item 3")
	itemToSelect.Selected = True
	RadListBox1.Items(0).Selected = True 

Finding items

You can locate an item 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 following RadListBox methods:

FindItemByText
FindItemByValue
FindItemIndexByValue

Collections of items

You can use the following collections of RadListBoxItem objects:

Items - retrieves a list of all items
SelectedItems - retrieves a list of all selected items
CheckedItems - retrieves a list of all checked items (when the CheckBoxes property is True)