Occurs before the contents of the
SelectedItems collection is changed.
The event handler receives an argument of type ItemSelectionChangingEventArgs containing data related to this event. The following ItemSelectionChangingEventArgs properties provide information specific to this event.
The following code sample demonstrates how to handle the UltraListView's ItemSelectionChanging event to prevent items in different groups from being selected, and also how to handle the ItemSelectionChanged event to change the appearance for selected items based on whether multiple items are selected:
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_ItemSelectionChanging(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinListView.ItemSelectionChangingEventArgs) Handles ultraListView1.ItemSelectionChanging
' Get a reference to the UltraListView control
Dim listView As UltraListView = CType(sender, UltraListView)
' Get a reference to the last member of the SelectedItems
' collection...note that it does not matter which member we use,
' we just need any currently selected item
Dim previousSelectedItem As UltraListViewItem = listView.SelectedItems.Last
' Iterate the SelectedItems collection passed through the
' event arguments this represents what the contents of the
' UltraListView's SelectedItems collection will become if this
' event is not canceled.
If listView.ShowGroups AndAlso Not previousSelectedItem Is Nothing Then
Dim selectedItem As UltraListViewItem
For Each selectedItem In e.SelectedItems
' If any member of the new SelectedItems collection is
' in a different group than the currently selected items,
' cancel the event.
If Not selectedItem.Group Is previousSelectedItem.Group AndAlso _
Not e.SelectedItems.First Is e.SelectedItems.Last Then
e.Cancel = True
Return
End If
Next
End If
End Sub
Private Sub ultraListView1_ItemSelectionChanged(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinListView.ItemSelectionChangedEventArgs) Handles ultraListView1.ItemSelectionChanged
' Get a reference to the UltraListView control
Dim listView As UltraListView = CType(sender, UltraListView)
' Apply a different appearance based on whether multiple items are selected
If (e.SelectedItems.Count > 1) Then
listView.ItemSettings.SelectedAppearance.BackColor = Color.LightBlue
listView.ItemSettings.SelectedAppearance.BackColor2 = SystemColors.Highlight
listView.ItemSettings.SelectedAppearance.BackGradientStyle = GradientStyle.Vertical
Else
listView.ItemSettings.SelectedAppearance.Reset()
End If
End Sub
using Infragistics.Win;
using Infragistics.Win.UltraWinListView;
using System.Diagnostics;
private void ultraListView1_ItemSelectionChanging(object sender, Infragistics.Win.UltraWinListView.ItemSelectionChangingEventArgs e)
{
// Get a reference to the UltraListView control
UltraListView listView = sender as UltraListView;
// Get a reference to the last member of the SelectedItems
// collection...note that it does not matter which member we use,
// we just need any currently selected item
UltraListViewItem previousSelectedItem = listView.SelectedItems.Last;
// Iterate the SelectedItems collection passed through the
// event arguments; this represents what the contents of the
// UltraListView's SelectedItems collection will become if this
// event is not canceled.
if ( listView.ShowGroups && previousSelectedItem != null )
{
foreach( UltraListViewItem selectedItem in e.SelectedItems )
{
// If any member of the new SelectedItems collection is
// in a different group than the currently selected items,
// cancel the event.
if ( selectedItem.Group != previousSelectedItem.Group &&
e.SelectedItems.First != e.SelectedItems.Last )
{
e.Cancel = true;
break;
}
}
}
}
private void ultraListView1_ItemSelectionChanged(object sender, Infragistics.Win.UltraWinListView.ItemSelectionChangedEventArgs e)
{
// Get a reference to the UltraListView control
UltraListView listView = sender as UltraListView;
// Apply a different appearance based on whether multiple items are selected
if ( e.SelectedItems.Count > 1 )
{
listView.ItemSettings.SelectedAppearance.BackColor = Color.LightBlue;
listView.ItemSettings.SelectedAppearance.BackColor2 = SystemColors.Highlight;
listView.ItemSettings.SelectedAppearance.BackGradientStyle = GradientStyle.Vertical;
}
else
listView.ItemSettings.SelectedAppearance.Reset();
}
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
