问使用PDF Clown实际裁剪PDF

EN

Dim reader As New PdfReader(sourcefile)
Dim doc As New Document()
Dim writer As PdfWriter = PdfWriter.GetInstance(doc, New System.IO.FileStream(outputfilename, System.IO.FileMode.Create))

//get the source page as an Imported Page
Dim page As PdfImportedPage = writer.GetImportedPage(reader, indexOfPageToGet) page

//create PDFTemplate Object at original size from source - see iText in Action book Page 91 for full details
Dim pdftemp As PdfTemplate = page.CreateTemplate(page.Width, page.Height) 
//paste the original page onto the template object, see iText documentation what those parameters do (scaling, mirroring)
pdftemp.AddTemplate(page, 1, 0, 0, 1, 0, 0)
//now the critical part - set .boundingBox property on the template. This makes all objects outside the rectangle invisible
pdftemp.boundingBox = {iText Rectangle Structure with new Cropbox}
//template not needed anymore
writer.ReleaseTemplate(pdftemp) 
//create an iText IMAGE object as wrapper to the template - with this img object absolute positionion on the final page is much easier
dim img as iTextSharp.Text.Image = Image.GetInstance(pdftemp)
// set img position
img.SetAbsolutePosition(x, y)
//set optional Rotation if needed
img.RotationDegrees = 0
//finally, this adds the actual content to the new document
doc.Add(img) 
//cleanup
doc.Close()
reader.Close()
writer.Close()