The following sample code illustrates some of the information available in the BeforeSelect event.
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.UltraWinTree
Private Sub ultraTree1_BeforeSelect(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinTree.BeforeSelectEventArgs) Handles ultraTree1.BeforeSelect
Dim sb As New System.Text.StringBuilder()
sb.Append("The SelectedNodes collection is about to change to the nodes ")
Dim node As UltraTreeNode
' Loop over the nodes that will be in the new SelectedNodes collection.
' Note: The Nodes collection exposed by the event args
' is read-only.
For Each node In e.NewSelections
sb.Append(node.Key)
sb.Append(", ")
Next
sb.Append(" Press ''OK'' or ''Cancel''.")
Dim dr As DialogResult
dr = MessageBox.Show(Me, _
sb.ToString(), _
"Selected nodes changing", _
MessageBoxButtons.OKCancel)
If dr = DialogResult.Cancel Then e.Cancel = True
End Sub
using System.Diagnostics;
using Infragistics.Win.UltraWinTree;
private void ultraTree1_BeforeSelect(object sender, Infragistics.Win.UltraWinTree.BeforeSelectEventArgs e)
{
System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append("The SelectedNodes collection is about to change to the nodes ");
// Loop over the nodes that will be in the new SelectedNodes collection.
// Note: The Nodes collection exposed by the event args
// is read-only.
foreach ( UltraTreeNode node in e.NewSelections )
{
sb.Append( node.Key );
sb.Append( ", " );
}
sb.Append(" Press ''OK'' or ''Cancel''.");
DialogResult dr = MessageBox.Show( this,
sb.ToString(),
"Selected nodes changing",
MessageBoxButtons.OKCancel );
if ( dr == DialogResult.Cancel )
e.Cancel = true;
}
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