Custom grouping, group by on more than one level

[Lars]

I am trying to implement custom grouping and can't get it working when i group on more than one level. Can you provide an example on how this ca be done.

[Julian Benkov]

Hello Lars,

You can use the Level argument of the CustomGrouping event handler to implement a custom grouping operation for more levels. Here is an example:

using System;
using System.Data;
using System.Windows.Forms;
using Telerik.WinControls.UI;

namespace Lab.Grid
{
    public partial class GridCustomGroupingForm : Form
    {
        private RadGridView gridView = new RadGridView();

        public GridCustomGroupingForm()
        {
            InitializeComponent();

            gridView.Dock = DockStyle.Fill;
            gridView.Parent = this;
            gridView.EnableCustomGrouping = true;
            gridView.CustomGrouping += gridView_CustomGrouping;

            DataTable table = new DataTable();
            table.Columns.Add("Id");
            table.Columns.Add("Name");
            table.Columns.Add("Col3");

            table.Rows.Add(1, "Name1");
            table.Rows.Add(2, "Name12");
            table.Rows.Add(3, "Name12");
            table.Rows.Add(4, "Name1234");
            table.Rows.Add(5, "Name123");
            table.Rows.Add(6, "Name123456");
            table.Rows.Add(7, "Name1234567");
            table.Rows.Add(8, "Name123456");

            gridView.DataSource = table;
        }

        void gridView_CustomGrouping(object sender, GridViewCustomGroupingEventArgs e)
        {
            string colName = gridView.GroupDescriptors[e.Level].GroupNames[0].PropertyName;

            if (colName == "Id")
            {
                int val = Convert.ToInt32(e.Row.Cells[colName].Value);
                e.GroupKey = val % 2;
            }
            else if (colName == "Name")
            {
                e.GroupKey = e.Row.Cells[colName].Value.ToString().Length;
            }
        }
    }
}

I hope this helps.

Kind regards,
Julian Benkov
the Telerik team

[Lars]

This was what I was looking for, thank you!