Infragistics2.Win.UltraWinTree.v8.1
BeforeSelect Event
See Also  Example
Infragistics.Win.UltraWinTree Namespace > UltraTree Class : BeforeSelect Event

Occurs before a tree node is selected.

Syntax

Visual Basic (Declaration) 
Public Event BeforeSelect() As BeforeNodeSelectEventHandler
C# 
public event BeforeNodeSelectEventHandler BeforeSelect()

Remarks

The BeforeSelectEventArgs.NewSelections property of the BeforeSelectEventArgs contains a collection of the UltraTreeNode objects that are about to be selected.

Setting the Cancel property to true will prevent the UltraTreeNode objects from being selected.

Example

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.

Visual BasicCopy Code
    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

C#Copy Code
       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;
       
       }

See Also