Reputation: 99
I'm lost at the moment. What I try to accomplish is adding one PDF on another (like a watermark). The problem is that I dont seems to understand the coordinate system that is used because my watermark just behaves unexpected.
The two PDFs have different dimensions.
My target has the following dimensions:
595 height
842 width
The PDF that shall be added has this dimension:
41 height
552 width
In my code I do the following:
public bool AddPdf(ref PdfReader pdfSource, ref PdfReader pdfTarget, ref FileStream destination)
{
PdfStamper stamper = null;
try
{
stamper = new PdfStamper( pdfSource, destination );
PdfImportedPage importatedPage = stamper.GetImportedPage(pdfTarget, 1);
PdfContentByte background;
for (int iPage = 1; iPage <= pdfSource.NumberOfPages; iPage++)
{
background = stamper.GetOverContent(iPage);
background.AddTemplate(importatedPage, 0, 0 + importHeight);
}
}
When I do this I would expect my watermark to appear in the bottom left. Instead it is somewhere of the page (I dont see it). Just for testing I hardcoded 600 as y position and then it is centered vertically on the page.
Can someone give me a tip please?
Upvotes: 2
Views: 1915
Reputation: 99
So i solved the issue. The problem was that the sourcepdf had a cropbox - i only needed to correct my x and y position with that information:
PdfStamper stamper = null;
try
{
stamper = new PdfStamper(pdfSource, destination);
PdfImportedPage importatedPage = stamper.GetImportedPage(pdfTarget, 1);
PdfContentByte background;
for (int iPage = 1; iPage <= pdfSource.NumberOfPages; iPage++)
{
background = stamper.GetOverContent(iPage);
// here comes the important part
Rectangle cropBox = pdfSource.GetCropBox(iPage);
float xCorrected = 0 + cropBox.Left;
float yCorrected = 0 + cropBox.Bottom;
background.AddTemplate(importatedPage, xCorrected, yCorrected);
}
}
Take in mind that in case the pdf that you want to stamp on your original has also a cropbox, you need to reduce the x,y by x,y of that cropbox again.
Upvotes: 3