Creating multiple pages with PDFsharp using C#

问题

I am using PDFsharp to create a PDF page. This works very well for a document with just one page. There will be a situation where the rows will need to fill up two pages. Whenever the number of lines is equal to 20, I will like to create a new page and write the remaining content to it.

This code writes content on the first page but once the number of lines equals 20 it will continue to write on the first page and not go to the second.

How do I fix this please?

PdfDocument document = new PdfDocument();
document.Info.Title = "Created with PDFsharp";

// Create an empty page
PdfPage page = document.AddPage();

//page.Width = 
//page.Height = 

// Get an XGraphics object for drawing
XGraphics gfx = XGraphics.FromPdfPage(page);

//XPdfFontOptions options = new XPdfFontOptions(PdfFontEncoding.Unicode, PdfFontEmbedding.Always);

// Create a font
XFont font = new XFont("Times New Roman", 8, XFontStyle.BoldItalic);

int headeroneX = 30;
int headerOney = 25;
Int32 countLines = 0;

foreach (var item in queryResult)
{
    if ((playerIndex % TotalNumberOfUsersInGrp) == 0)
    {
        gfx.DrawString("Group:" + groupindex, font, XBrushes.DarkRed, new XRect(headeroneX, headerOney, page.Width, page.Height), XStringFormats.TopLeft);
        groupindex++;           
        headerOney = headerOney + 12;
    }
    gfx.DrawString(item.FullName + ',' + item.Rating, font, XBrushes.Black, new XRect(headeroneX, headerOney, page.Width, page.Height), XStringFormats.TopLeft);
    playerIndex++;
    headerOney = headerOney + 12;
    countLines = countLines + 1;

    if (countLines == 20)
    {
        countLines = 1;
        headerOney = 25;
        document.AddPage();
        gfx.DrawString(item.FullName + ',' + item.Rating, font, XBrushes.Black, new XRect(headeroneX, headerOney, page.Width, page.Height), XStringFormats.TopLeft);
    }
}

回答1:

I'm sure this is a duplicate.

You call AddPage() to create the second page, but continue to use the XGraphics object you created for the first page. You have to use the return value of AddPage() to create a new XGraphics object.

Duplicate of this question:
https://stackoverflow.com/a/21143712/1015447

The other chap tried to create a new XGraphics object, but also did not use the return value of AddPage().

Update: Untested code - I hope it compiles.

if (countLines == 20)
{
    countLines = 1;
    headerOney = 25;
    // Wrong: document.AddPage();
    // Better:
    page = document.AddPage();
    // Also missing:
    gfx = XGraphics.FromPdfPage(page);
    gfx.DrawString(item.FullName + ',' + item.Rating, font, XBrushes.Black, new XRect(headeroneX, headerOney, page.Width, page.Height), XStringFormats.TopLeft);
}

回答2:

It's a somewhat aged topic or thread but adding some input to clarify.

user2320476 is wrong. You are able (and allowed) to use XGraphics.FromPdfPage(page); twice in a page.

Just make sure you dispose of the first one and you're all set.

Using (XGraphics gfx = XGraphics.FromPdfPage(page))
{ MakeItRain(); }

if (gfx == null)
gfx.Dispose();
XGraphics gfx = XGraphics.FromPdfPage(page);

What he/she probably refers to is that the page isn't allowed to have multiple active XGraphics objects.

来源：https://stackoverflow.com/questions/32488019/creating-multiple-pages-with-pdfsharp-using-c-sharp

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c#-4.0

pdfsharp