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.NET and JavaScript UI Controls
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ItemCheckStateChanging Event

Occurs before the value of the CheckState property of an UltraListViewItem is changed.
Syntax
'Declaration
 
Public Event ItemCheckStateChanging As ItemCheckStateChangingEventHandler
public event ItemCheckStateChangingEventHandler ItemCheckStateChanging
Event Data

The event handler receives an argument of type ItemCheckStateChangingEventArgs containing data related to this event. The following ItemCheckStateChangingEventArgs properties provide information specific to this event.

PropertyDescription
Cancel (Inherited from System.ComponentModel.CancelEventArgs) 
Item (Inherited from Infragistics.Win.UltraWinListView.CancelableItemEventArgs)Returns the UltraListViewItem with which this instance is associated.
NewValue Gets/sets the new value for the associated UltraListViewItem object's CheckState property.
Example
The following code sample demonstrates how to handle the UltraListView's ItemCheckStateChanging and ItemCheckStateChanged events to allow only one checked item per group, and to activate and select the checked item after it is checked:

For an overview of how to handle events in Visual Basic or Visual C#, see Event Handlers in Visual Basic and Visual C#. For specific information and code examples illustrating how to consume events in your application, see Consuming Events in the .NET Framework Developer's Guide.

Imports Infragistics.Win
Imports Infragistics.Win.UltraWinListView

    Private Sub ultraListView1_ItemCheckStateChanging(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinListView.ItemCheckStateChangingEventArgs) Handles ultraListView1.ItemCheckStateChanging

        Dim listView As UltraListView = CType(sender, UltraListView)

        Try

            '	Disable the ItemCheckStateChanging and ItemCheckStateChanged events,
            '	so that we don't cause infinite recursion by setting the CheckState
            '	property in response to this event.
            listView.EventManager.Disable(UltraListViewEventIds.ItemCheckStateChanging)
            listView.EventManager.Disable(UltraListViewEventIds.ItemCheckStateChanged)

            If listView.ShowGroups AndAlso e.NewValue = CheckState.Checked Then

                Dim group As UltraListViewGroup = e.Item.Group

                '	Iterate the group's Items collection, and uncheck
                '	all other items except for this one
                Dim item As UltraListViewItem
                For Each item In group.Items
                    If Not item Is e.Item Then item.CheckState = CheckState.Unchecked
                Next
            End If

		Finally

            '	Re-enable the ItemCheckStateChanging and ItemCheckStateChanged events
            listView.EventManager.Enable(UltraListViewEventIds.ItemCheckStateChanging)
            listView.EventManager.Enable(UltraListViewEventIds.ItemCheckStateChanged)
        End Try
    End Sub

    Private Sub ultraListView1_ItemCheckStateChanged(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinListView.ItemCheckStateChangedEventArgs) Handles ultraListView1.ItemCheckStateChanged

        Dim listView As UltraListView = CType(sender, UltraListView)

        '	Activate and select the item that was checked
        e.Item.Activate()
        listView.PerformAction(UltraListViewAction.SelectItem, False, False)
    End Sub
using Infragistics.Win;
using Infragistics.Win.UltraWinListView;
using System.Diagnostics;


		private void ultraListView1_ItemCheckStateChanging(object sender, Infragistics.Win.UltraWinListView.ItemCheckStateChangingEventArgs e)
		{
			UltraListView listView = sender as UltraListView;
			
			try
			{
				//	Disable the ItemCheckStateChanging and ItemCheckStateChanged events,
				//	so that we don't cause infinite recursion by setting the CheckState
				//	property in response to this event.
				listView.EventManager.Disable(UltraListViewEventIds.ItemCheckStateChanging);
				listView.EventManager.Disable(UltraListViewEventIds.ItemCheckStateChanged);

				if ( listView.ShowGroups && e.NewValue == CheckState.Checked )
				{
					UltraListViewGroup group = e.Item.Group;

					//	Iterate the group's Items collection, and uncheck
					//	all other items except for this one
					foreach( UltraListViewItem item in group.Items )
					{
						if ( item != e.Item )
							item.CheckState = CheckState.Unchecked;
					}
				}
			}
			finally
			{
				//	Re-enable the ItemCheckStateChanging and ItemCheckStateChanged events.
				listView.EventManager.Enable(UltraListViewEventIds.ItemCheckStateChanging);
				listView.EventManager.Enable(UltraListViewEventIds.ItemCheckStateChanged);
			}
		}

		private void ultraListView1_ItemCheckStateChanged(object sender, Infragistics.Win.UltraWinListView.ItemCheckStateChangedEventArgs e)
		{
			UltraListView listView = sender as UltraListView;

			//	Activate and select the item that was checked
			e.Item.Activate();
			listView.PerformAction( UltraListViewAction.SelectItem, false, false );
		}
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also