How to: Select Nodes That Meet the Specified Criteria

Dec 17, 2020

This example demonstrates how to select departments whose budget is greater than $500,000.

The ‘ Do Select ‘ button’s Click event is handled to call the ASPxClientTreeList.PerformCustomCallback method.

This sends a callback to the server and generates the ASPxTreeList.CustomCallback event. This event is handled to select the required departments. To traverse through the nodes, the Node Iterator is used.

The image below shows the result:

C#
VB.NET

csharp

using DevExpress.Web.ASPxTreeList;

protected void ASPxTreeList1_CustomCallback(object sender,
DevExpress.Web.ASPxTreeList.TreeListCustomCallbackEventArgs e) {
    TreeListNodeIterator iterator = ASPxTreeList1.CreateNodeIterator();
    TreeListNode node;
    while (true) {
        node = iterator.GetNext();
        if (node == null) break;
        if ((decimal)node["BUDGET"] > 500000M)
            node.Selected = true;
    }
}

Imports DevExpress.Web.ASPxTreeList

Protected Sub ASPxTreeList1_CustomCallback(ByVal sender As Object,_
ByVal e As DevExpress.Web.ASPxTreeList.TreeListCustomCallbackEventArgs)
   Dim iterator As TreeListNodeIterator = ASPxTreeList1.CreateNodeIterator()
   Dim node As TreeListNode
   Do While True
      node = iterator.GetNext()
      If node Is Nothing Then
      Exit Do
      End If
      If CDec(node("BUDGET")) > 500000D Then
         node.Selected = True
      End If
   Loop
End Sub