private void arv_Load(object sender, System.EventArgs e)
{
    rptDD rpt = new rptDD();
    rpt.Run();
    arv.Document = rpt.Document;

    SizeF sz = arv.Document.Pages[0].MeasureText("This is my string. How long is it?");
    arv.Document.Pages[0].DrawText("This is my string. How long is it? " + sz.ToString(),0,0,6f,9f);
    arv.Document.Pages[0].DrawLine(0,sz.Height,sz.Width,sz.Height);
}

Private Sub arv_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles arv.Load
    Dim rpt As New rptDD
    rpt.Run()
    arv.Document = rpt.Document

    Dim sz As SizeF = arv.Document.Pages(0).MeasureText("This is my string. How long is it?")
    arv.Document.Pages(0).DrawText("This is my string. How long is it? " + sz.ToString(), 0, 0, 6.0F, 9.0F)
    arv.Document.Pages(0).DrawLine(0, sz.Height, sz.Width, sz.Height)
End Sub