Virtual Mode and Groups

[Werner Depenbrock]

Hello,

I have a RadGridView generated with many rows. This grid is in virtual mode. Now I want to generate groups. The GroupByExpression property doesn't work. How can I generate groups in virtual mode?

[Julian Benkov]

Hello Werner Depenbrock,

Sorry for the delay of my answer.

You can use the new virtual grouping functionality in RadGridView. When grid is in virtual mode you can handle also the DataGroupNeeded event:

public partial class VirtualForm : Form
{
    public VirtualForm()
    {
        InitializeComponent();
    }

    Random rand = new Random(1000);
    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);

        this.radGridView1.ColumnCount = 10;
        this.radGridView1.RowCount = 100;

        for (int i = 0; i < this.radGridView1.ColumnCount; i++)
        {
            this.radGridView1.Columns[i].HeaderText = this.radGridView1.Columns[i].UniqueName;
        }

        this.radGridView1.MasterGridViewTemplate.BestFitColumns();
    }

    private void radGridView1_CellValueNeeded(object sender, Telerik.WinControls.UI.GridViewCellValueEventArgs e)
    {
        e.Value = rand.Next();
    }

    private void radGridView1_DataGroupNeeded(object sender, Telerik.WinControls.UI.GridViewDataGroupEventArgs e)
    {
        if (e.Expression.GroupByFields[0].FieldName == "Column5")
        {
            e.GroupCount = 5;

            e.HeaderText[0] = "TestGroup1";
            e.RowCount[0] = 20;

            e.HeaderText[1] = "TestGroup2";
            e.RowCount[1] = 20;

            e.HeaderText[2] = "TestGroup3";
            e.RowCount[2] = 20;

            e.HeaderText[3] = "TestGroup4";
            e.RowCount[3] = 20;

            e.HeaderText[4] = "TestGroup5";
            e.RowCount[4] = 20;
        }
    }
}

Do not hesitate to write me back if you have further questions.

Regards,
Julian Benkov
the Telerik team

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