C#

private void DrawInvoiceItemsTable(PdfContents contents, Invoice invoice)
        {
            contents.SaveGraphicsState();
            contents.Translate(0, 0);
            const double col1X = 2.2;
            const double baseY = 19.25;
            const double col2X = 11.1;
            const double col5X = 16;
            contents.SetColorNonStroking(Color.FromArgb(40, 171, 226));
            contents.DrawRectangle(1.9, 19, 8.5, 0.8, PaintOp.Fill);
            contents.DrawText(ArialBold, 10.0, col1X, baseY, TextJustify.Left, DrawStyle.Normal, Color.White, "ITEM DESCRIPTION");
            contents.DrawRectangle(10.45, 19, 4.2, 0.8, PaintOp.Fill);
            contents.DrawText(ArialBold, 10.0, col2X, baseY, TextJustify.Left, DrawStyle.Normal, Color.White, "POINTS ISSUED");
            contents.DrawRectangle(14.7, 19, 5.5, 0.8, PaintOp.Fill);
            contents.DrawText(ArialBold, 10.0, col5X, baseY, TextJustify.Left, DrawStyle.Normal, Color.White, "TOTAL AMOUNT");
            contents.RestoreGraphicsState();

            var box = new TextBox(7.9);
            var posY = 18.6;
            const double fontSize = 9.0;
            var lineSpace = ArialNormal.LineSpacing(fontSize);
            var decent = ArialNormal.Descent(fontSize);
            const double lineHeight = 0.3;
            contents.SaveGraphicsState();
            contents.Translate(0, 0);
            for (var i = 0; i < invoice.InvoiceCharges.Count; i++)
            {
                box.Clear();
                if (i % 2 != 0)
                {
                    contents.SetColorNonStroking(Color.FromArgb(230, 230, 230));
                    contents.DrawRectangle(1.9, posY - lineSpace * 1.5, 8.5, lineHeight + lineSpace, PaintOp.Fill);
                    contents.DrawRectangle(10.45, posY - lineSpace * 1.5, 4.2, lineHeight + lineSpace, PaintOp.Fill);
                    //contents.DrawRectangle(12.6, PosY - lineSpace * 1.5, 2.1, lineHeight + lineSpace, PaintOp.Fill);
                    contents.DrawRectangle(14.7, posY - lineSpace * 1.5, 5.5, lineHeight + lineSpace, PaintOp.Fill);
                    //contents.DrawRectangle(16.9, PosY - lineSpace * 1.5, 3, lineHeight + lineSpace, PaintOp.Fill);
                }
                box.AddText(ArialNormal, fontSize, Color.FromArgb(85, 86, 89), invoice.InvoiceCharges[i].Description);
                contents.DrawText(col1X, ref posY, 0, 0, box);
                posY += decent;
                contents.DrawText(ArialNormal, fontSize, col2X, posY, TextJustify.Left, DrawStyle.Normal, Color.FromArgb(85, 86, 89), invoice.InvoiceCharges[i].PointsIssued);
                //contents.DrawText(ArialNormal, fontSize, col3X, PosY, TextJustify.Left, DrawStyle.Normal, Color.FromArgb(85, 86, 89), invoice.InvoiceCharges[i].Amount.ToString("c2"));
                //contents.DrawText(ArialNormal, fontSize, col4X, PosY, TextJustify.Left, DrawStyle.Normal, Color.FromArgb(85, 86, 89), invoice.InvoiceCharges[i].GstRate.ToString("n2"));
                contents.DrawText(ArialNormal, fontSize, col5X, posY, TextJustify.Left, DrawStyle.Normal, Color.FromArgb(85, 86, 89), invoice.InvoiceCharges[i].Amount.ToString("c2"));

                posY -= decent + lineSpace;
            }
            contents.DrawText(ArialNormal, 10.0, 15.2, 6.5, TextJustify.Left, DrawStyle.Normal, Color.FromArgb(85, 86, 89), "Subtotal");
            contents.DrawText(ArialNormal, 10.0, 19, 6.5, TextJustify.Right, DrawStyle.Normal, Color.Black, invoice.SubTotal.ToString("c2"));
            contents.DrawText(ArialNormal, 10.0, 15.2, 6, TextJustify.Left, DrawStyle.Normal, Color.FromArgb(85, 86, 89), "GST");
            contents.DrawText(ArialNormal, 10.0, 19, 6, TextJustify.Right, DrawStyle.Normal, Color.Black, invoice.GstTotal.ToString("c2"));
            contents.SetColorNonStroking(Color.FromArgb(40, 171, 226));
            contents.DrawRectangle(14.75, 5, 2.1, 0.8, PaintOp.Fill);
            contents.DrawRectangle(16.9, 5, 3, 0.8, PaintOp.Fill);
            contents.DrawText(ArialBold, 10.0, 15.2, 5.25, TextJustify.Left, DrawStyle.Normal, Color.White, "TOTAL");
            contents.DrawText(ArialBold, 10.0, 18.5, 5.25, TextJustify.Center, DrawStyle.Normal, Color.White, invoice.TotalAmount.ToString("c2"));
        }

public class BaseClass
{
    public void ShowMe() {MessageBox.Show("BaseClass");}
}

public class DerivedClass1: BaseClass
{
    public void ShowMe(){MessageBox.Show("DerivedClass1");}
}
    
public class DerivedClass2: BaseClass 
{ 
    public void ShowMe(){MessageBox.Show("DerivedClass2");}
}

BaseClass baseClass = new BaseClass();
DerivedClass1 derivedClass1 = new DerivedClass1();
DerivedClass2 derivedClass2 = new DerivedClass2();

private void invokeClassMethod1(BaseClass theClass) {theClass.ShowMe();}
    
private void invokeClassMethod2(dynamic theClass) { theClass.ShowMe(); }
    
private void invokeClassMethod3(BaseClass theClass)
{
    if(theClass is DerivedClass1)
    {
        (theClass as DerivedClass1).ShowMe();
    } else if (theClass is DerivedClass2)
    {
        (theClass as DerivedClass2).ShowMe();
    }
    else
    {
        theClass.ShowMe();
    }
}