我正在使用iTextSharp 5.0.6来读取现有的PDF,在每个页面上迭代每个页面标记文本,然后写出新加盖的PDF.我面临的问题是,这不是100%的工作时间.对于某些PDF,每个页面都按预期标记,对于其他页面,大多数页面都会加盖,而有些页面则没有.看起来似乎存在压模的GetOverContent()没有返回最顶层的问题,但这只是一个假设.有没有人有类似的问题?
using iTextSharp.text;
using iTextSharp.text.pdf;
const string WATERMARK_TEXT = "John Doe";
static void Main(string[] args)
{
string masterPdf = "master.pdf";
string pdfToCreate = "watermark.pdf";
byte[] bytes = StampPDF(masterPdf);
using (FileStream stream = new FileStream(pdfToCreate, FileMode.Create))
{
stream.Write(bytes, 0, bytes.Length);
}
}
static byte[] StampPDF(string PdfPath)
{
using (MemoryStream memoryStream = new MemoryStream())
{
PdfReader reader = new PdfReader(PdfPath);
int pageCount = reader.NumberOfPages;
PdfStamper stamper = new PdfStamper(reader, memoryStream);
float fontSize = 9;
float textAngle = 0f;
BaseFont font = BaseFont.CreateFont(BaseFont.TIMES_ROMAN, BaseFont.WINANSI, BaseFont.EMBEDDED);
BaseColor backgroundColor = new BaseColor(0, 0, 0);
BaseColor fontColor = new BaseColor(255, 255, 255);
float padding = 2f;
float fontWidth = font.GetWidthPoint(WATERMARK_TEXT, fontSize);
iTextSharp.text.Rectangle pageSize;
PdfContentByte pageContents;
for (int i = 1; i <= pageCount; i++)
{
pageSize = reader.GetPageSize(i);
pageContents = stamper.GetOverContent(i);
//draw a rectangle
pageContents.SetColorFill(backgroundColor);
pageContents.MoveTo(pageSize.Width - (fontWidth + padding), 0f);
pageContents.LineTo(pageSize.Width, 0f);
pageContents.LineTo(pageSize.Width, 14f);
pageContents.LineTo(pageSize.Width - (fontWidth + padding), 14f);
pageContents.Fill();
//drop our watermark on top of the rectangle we just created
pageContents.BeginText();
pageContents.SetColorFill(fontColor);
pageContents.SetFontAndSize(font, fontSize);
pageContents.ShowTextAligned(PdfContentByte.ALIGN_LEFT, WATERMARK_TEXT, pageSize.Width - fontWidth, 4, textAngle);
pageContents.EndText();
}
stamper.Close();
reader.Close();
return memoryStream.ToArray();
}
}
最佳答案 对于那些可能遇到同样问题的人来说,关键是检查CropBox.由于PDF的CropBox的尺寸可能小于其PageSize的尺寸,因此您需要有条件地使用其中一个.因此,基于上面的代码示例,for循环将被更改为:
for (int i = 1; i <= pageCount; i++)
{
mediaBox = reader.GetPageSize(i);
cropBox = reader.GetCropBox(i);
overContent = stamper.GetOverContent(i);
if (cropBox != null && (cropBox.Width < mediaBox.Width || cropBox.Height < cropBox.Height))
mediaBox = cropBox;
//draw a rectangle
overContent.SetColorFill(backgroundColor);
overContent.MoveTo(mediaBox.Right - (fontWidth + fontPadding), mediaBox.Bottom);
overContent.LineTo(mediaBox.Right, mediaBox.Bottom);
overContent.LineTo(mediaBox.Right, mediaBox.Bottom + rectangleHeight);
overContent.LineTo(mediaBox.Right - (fontWidth + fontPadding), mediaBox.Bottom + rectangleHeight);
overContent.ClosePathFillStroke();
//drop our watermark on top of the rectangle we just created
overContent.BeginText();
overContent.SetColorFill(fontColor);
overContent.SetFontAndSize(font, fontSize);
overContent.ShowTextAligned(PdfContentByte.ALIGN_LEFT, WATERMARK_TEXT, mediaBox.Right - fontWidth, mediaBox.Bottom + (rectangleHeight - fontSize), textAngle);
overContent.EndText();
}