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

Occurs before the UltraTreeNode.CheckedState of a node is changed.

Syntax

Visual Basic (Declaration) 
Public Event BeforeCheck() As BeforeCheckEventHandler
C# 
public event BeforeCheckEventHandler BeforeCheck()

Remarks

The CancelableNodeEventArgs.TreeNode property of the CancelableNodeEventArgs contains a reference to UltraTreeNode whose UltraTreeNode.CheckedState is about to change.

Setting the Cancel property to true will prevent the UltraTreeNode.CheckedState of the UltraTreeNode from changing.

The BeforeCheckEventArgs.NewValue parameter gets/sets the new value of the UltraTreeNode.CheckedState property of the UltraTreeNode.

This event applies only to nodes whose Override.NodeStyle is set to CheckBox, CheckBoxTripleState, or OptionButton.

Example

The following sample code illustrates some of the information available in the BeforeCheck 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_BeforeCheck(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinTree.BeforeCheckEventArgs) Handles ultraTree1.BeforeCheck

        Dim sb As New System.Text.StringBuilder()

        sb.Append("Node: ")
        sb.Append(e.TreeNode.Key)
        sb.Append(" check state is about to change from ")
        sb.Append(e.TreeNode.CheckedState)
        sb.Append(" to ")
        sb.Append(e.NewValue)

        Debug.WriteLine(sb.ToString())

        ' Note : This action can be canceled by the following line of code.
        'e.Cancel = True

    End Sub

C#Copy Code
       using System.Diagnostics;
       using Infragistics.Win.UltraWinTree;

       private void ultraTree1_BeforeCheck(object sender, Infragistics.Win.UltraWinTree.BeforeCheckEventArgs e)
       {

           System.Text.StringBuilder sb = new System.Text.StringBuilder();

           sb.Append("Node: ");
           sb.Append(e.TreeNode.Key);
           sb.Append(" check state is about to change from ");
           sb.Append(e.TreeNode.CheckedState);
           sb.Append(" to ");
           sb.Append(e.NewValue);

           Debug.WriteLine( sb.ToString() );
       
           // Note : This action can be canceled by the following line of code.
           //e.Cancel = true;

       }

See Also