附件pdf

Question

我有各种pdf文件说file1.pdf，file2.pdf .......... 现在我想创建一个新的pdf文档，说MainDoc.pdf。 此MainDoc.pdf将包含File1.pdf，File2.pdf ...作为附件。

尝试了这段代码，但它给出了错误： “Object Refrence not set to an instance”

its.Document PDFD = new its.Document(its.PageSize.LETTER);
its.pdf.PdfWriter writer;
writer = its.pdf.PdfWriter.GetInstance(PDFD, new FileStream(targetpath, FileMode.Create));
its.pdf.PdfFileSpecification pfs = its.pdf.PdfFileSpecification.FileEmbedded(writer, "C:\\test.xml", "New.xml", null);
writer.AddFileAttachment(pfs);

看起来问题与作家有关。

对象引用未设置为对象的实例。在iTextSharp.text.pdf.PdfWriter.get_PdfIndirectReference（）

Answer 1

您是否检查过'writer'和'PdfFileSpecification'不为空？

Answer 2

Null来自文件。

添加

PDFD.Open();

之后

its.pdf.PdfWriter writer = its.pdf.PdfWriter.GetInstance(PDFD, new FileStream(targetpath, FileMode.Create));

Answer 3

我假设最后一行发生错误？检查pfs - 是否已分配？

its.Document PDFD = new its.Document(its.PageSize.LETTER);
its.pdf.PdfWriter writer = its.pdf.PdfWriter.GetInstance(PDFD, new FileStream(targetpath, FileMode.Create));
its.pdf.PdfFileSpecification pfs = its.pdf.PdfFileSpecification.FileEmbedded(writer, "C:\\test.xml", "New.xml", null);
if( pfs )
{
    writer.AddFileAttachment(pfs);
}
else
{
    // An error occurred!
}