How to: Enable Recursive Selection When Binding at Runtime

• Dec 17, 2020

This example shows how you should bind the ASPxTreeList at runtime to enable recursive selection.

C#

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.OleDb;
using DevExpress.Web.ASPxTreeList;

public partial class _Default : System.Web.UI.Page {
    protected override void OnInit(EventArgs e) {
        base.OnInit(e);
        InitTreeList(ASPxTreeList1);
    }

    protected void Page_Load(object sender, EventArgs e) {
        ASPxTreeList1.DataBind();
    }

    OleDbDataAdapter CreateDataAdapter() {
        string connectionString =
         @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Databases\Departments.mdb";
        OleDbConnection myConnection = new OleDbConnection(connectionString);
        string query =
        "SELECT [ID], [ParentID], [Department], [Budget], [Location] FROM [Departments]";
        return new OleDbDataAdapter(query, myConnection);
    }
    DataTable CreateDataTable(OleDbDataAdapter myAdapter) {
        DataTable dt = new DataTable();
        DataSet testData = new DataSet();
        myAdapter.Fill(testData);
        return testData.Tables[0];
    }
    void InitTreeList(ASPxTreeList tl) {
        tl.SettingsSelection.Recursive = true;
        tl.SettingsSelection.AllowSelectAll = true;
        tl.SettingsSelection.Enabled = true;
        tl.KeyFieldName = "ID";
        tl.ParentFieldName = "ParentID";
        ASPxTreeList1.DataSource = CreateDataTable(CreateDataAdapter());
    }
}