我的代码如下所示

using (MemoryStream memoria = new MemoryStream())
        {
            Document pdf = new Document(new Rectangle(288,144));

            try
            {
                PdfWriter writer = PdfWriter.GetInstance(pdf,memoria);

                pdf.Open();
                pdf.SetMargins(0,0);

                PdfPTable tPrincipal = new PdfPTable(2);            
                tPrincipal .WidthPercentage = 100;           
                tPrincipal .DefaultCell.Border = 0;
                tPrincipal .TotalWidth = 288f;
                tPrincipal .LockedWidth = true;

….

我只是不能将上边距设置为0.它只是不关心我的设置为(0,0)并留下一个上边距(约50f).