Default.aspx.cs

using DevExpress.Web;
using System;
using System.Collections;
using System.Data;
using System.Web.UI;

namespace WebApp {
    public partial class Default : System.Web.UI.Page {
        DataSet ds = null;
        protected void Page_Init(object sender, EventArgs e) {
            if (!IsPostBack || (Session["DataSet"] == null)) {
                ds = new DataSet();
                DataTable masterTable = new DataTable();
                masterTable.Columns.Add("ID", typeof(int));
                masterTable.Columns.Add("Data", typeof(string));
                masterTable.PrimaryKey = new DataColumn[] { masterTable.Columns["ID"] };

                DataTable detailTable = new DataTable();
                detailTable.Columns.Add("ID", typeof(int));
                detailTable.Columns.Add("MasterID", typeof(int));
                detailTable.Columns.Add("Data", typeof(string));
                detailTable.PrimaryKey = new DataColumn[] { detailTable.Columns["ID"] };
                int index = 0;
                for (int i = 0; i < 20; i++) {
                    masterTable.Rows.Add(new object[] { i, "Master Row " + i });
                    for (int j = 0; j < 5; j++)
                        detailTable.Rows.Add(new object[] { index++, i, "Detail Row " + j });
                }
                ds.Tables.AddRange(new DataTable[] { masterTable, detailTable });
                Session["DataSet"] = ds;
            }
            else
                ds = (DataSet)Session["DataSet"];
            MasterGridView.DataSource = ds.Tables[0];
            MasterGridView.DataBind();
        }
        protected void DetailGridView_BeforePerformDataSelect(object sender, EventArgs e) {
            ds = (DataSet)Session["DataSet"];
            DataTable detailTable = ds.Tables[1];
            DataView dv = new DataView(detailTable);
            ASPxGridView detailGridView = (ASPxGridView)sender;
            dv.RowFilter = "MasterID = " + detailGridView.GetMasterRowKeyValue();
            detailGridView.DataSource = dv;
        }
        protected void MasterGridView_RowUpdating(object sender, DevExpress.Web.Data.ASPxDataUpdatingEventArgs e) {
            ds = (DataSet)Session["DataSet"];
            ASPxGridView gridView = (ASPxGridView)sender;
            DataTable dataTable = gridView.GetMasterRowKeyValue() != null ? ds.Tables[1] : ds.Tables[0];
            DataRow row = dataTable.Rows.Find(e.Keys[0]);
            IDictionaryEnumerator enumerator = e.NewValues.GetEnumerator();
            enumerator.Reset();
            while (enumerator.MoveNext())
                row[enumerator.Key.ToString()] = enumerator.Value;
            gridView.CancelEdit();
            e.Cancel = true;
        }
        protected void MasterGridView_RowInserting(object sender, DevExpress.Web.Data.ASPxDataInsertingEventArgs e) {
            ds = (DataSet)Session["DataSet"];
            ASPxGridView gridView = (ASPxGridView)sender;
            DataTable dataTable = gridView.GetMasterRowKeyValue() != null ? ds.Tables[1] : ds.Tables[0];
            DataRow row = dataTable.NewRow();
            e.NewValues["ID"] = GetNewId();
            IDictionaryEnumerator enumerator = e.NewValues.GetEnumerator();
            enumerator.Reset();
            while (enumerator.MoveNext())
                if (enumerator.Key.ToString() != "Count")
                    row[enumerator.Key.ToString()] = enumerator.Value;
            gridView.CancelEdit();
            e.Cancel = true;
            dataTable.Rows.Add(row);
        }

        protected void MasterGridView_RowDeleting(object sender, DevExpress.Web.Data.ASPxDataDeletingEventArgs e) {
            int i = MasterGridView.FindVisibleIndexByKeyValue(e.Keys[MasterGridView.KeyFieldName]);
            Control c = MasterGridView.FindDetailRowTemplateControl(i, "ASPxGridView2");
            e.Cancel = true;
            ds = (DataSet)Session["DataSet"];
            ds.Tables[0].Rows.Remove(ds.Tables[0].Rows.Find(e.Keys[MasterGridView.KeyFieldName]));
        }

        private int GetNewId() {
            ds = (DataSet)Session["DataSet"];
            DataTable table = ds.Tables[0];
            if (table.Rows.Count == 0) return 0;
            int max = Convert.ToInt32(table.Rows[0]["ID"]);
            for (int i = 1; i < table.Rows.Count; i++) {
                if (Convert.ToInt32(table.Rows[i]["ID"]) > max)
                    max = Convert.ToInt32(table.Rows[i]["ID"]);
            }
            return max + 1;
        }
    }
}