PDFsharp page size and margin issue with C #

I am converting an image to pdf using the PDFsharp lib. I need to set the margin and page size so that I get a trick from this forum to set the page size and size. From here I got the code that I used, but I get an error for two areas. Here is the code I received.

page = document.AddPage();
//page.Size = PdfSharp.PageSize.A4;
XSize size = PageSizeConverter.ToSize(PdfSharp.PageSize.A4);
if(page.Orientation == PageOrientation.Landscape)
{
   page.Width  = size.Height;
   page.Height = size.Width;
}
else
{
   page.Width  = size.Width;
   page.Height = size.Height;
}

// default unit in points 1 inch = 72 points
page.TrimMargins.Top = 5;
page.TrimMargins.Right = 5;
page.TrimMargins.Bottom = 5;
page.TrimMargins.Left = 5;

I got an error for this line

XSize size = PageSizeConverter.ToSize(PdfSharp.PageSize.A4);

so i need to change it to

System.Drawing.Size size = PageSizeConverter.ToSize(PdfSharp.PageSize.A4);

Now my program compiles, but when I set the field, I raise an error PdfSharp does not contain a definition for TrimMargins

these lines below are not compiled to specify the field.

    pdfPage.TrimMargins.Top = 5;
    pdfPage.TrimMargins.Right = 5;
    pdfPage.TrimMargins.Bottom = 5;
    pdfPage.TrimMargins.Left = 5;

I am using pdf sharp library version 1.0.898.0

So tell me how I can set the margin.

Here is my complete code to create a pdf file from a file

public static string GeneratePdfFromImage(string source)
        {
            string destinaton = source.Replace("gif", "pdf");
            PdfDocument doc = new PdfDocument();
            PdfPage pdfPage = new PdfPage();
            System.Drawing.Size size = PageSizeConverter.ToSize(PdfSharp.PageSize.A4);
            pdfPage.Orientation = PageOrientation.Portrait;

            pdfPage.Width = size.Width;
            pdfPage.Height = size.Height;
            pdfPage.TrimMargins.Top = 5;
            pdfPage.TrimMargins.Right = 5;
            pdfPage.TrimMargins.Bottom = 5;
            pdfPage.TrimMargins.Left = 5;

            doc.Pages.Add(pdfPage);

            XGraphics xgr = XGraphics.FromPdfPage(doc.Pages[0]);
            XImage img = XImage.FromFile(source);

            try
            {
                xgr.DrawImage(img, 0, 0);
                doc.Save(destinaton);
                doc.Close();
            }
            catch (Exception ex)
            {
                destinaton = "";
            }

            return destinaton;
        }