我也不是在PowerShell中很好，但看起来你应该能够很容易地适应这个C＃代码。这篇文章中的代码改编自我之前此处编写的一些代码。

I'm not too good within PowerShell but it looks like you are so you should be able to adapt this C# code very easily. The code in this post is adapted from some code I wrote earlier here.

首先，我真的不建议保持全局iText抽象对象并反复绑定各种各样的东西，这只是在寻找麻烦。

First off, I really don't recommend keeping global iText abstraction objects around and binding various things to them over and over, that's just looking for trouble.

相反，对于图像，我建议使用一个简单的函数来获取提供的图像文件，并返回表示添加到PDF的图像的字节数组。您也可以将PDF写入临时文件而不是字节数组，而是返回该路径。

Instead, for images I'd recommend a simple function that takes a supplied image file and returns a byte array representing that image added to a PDF. Instead of a byte array you could also write the PDF to a temporary file and return that path instead.

private static byte[] ImageToPdf(string imagePath) {
    //Get the size of the current image
    iTextSharp.text.Rectangle pageSize = null;
    using (var srcImage = new Bitmap(imagePath)) {
        pageSize = new iTextSharp.text.Rectangle(0, 0, srcImage.Width, srcImage.Height);
    }

    //Simple image to PDF
    using (var m = new MemoryStream()) {
        using (var d = new Document(pageSize, 0, 0, 0, 0)) {
            using (var w = PdfWriter.GetInstance(d, m)) {
                d.Open();
                d.Add(iTextSharp.text.Image.GetInstance(imagePath));
                d.Close();
            }
        }

        //Grab the bytes before closing out the stream
        return m.ToArray();
    }
}

然后只需创建一个新的文档并将 PdfSmartCopy 对象绑定到它。然后，您可以枚举您的文件，如果您有图像，首先将其转换为PDF，然后只需使用 PdfSmartCopy 方法 AddDocument（）将整个文档添加到最终输出。

Then just create a new Document and bind a PdfSmartCopy object to it. You can then enumerate your files, if you have an image, convert it to a PDF first, then just use the PdfSmartCopy method AddDocument() to add that entire document to the final output.

下面的代码只循环遍历单个文件夹，首先抓取图像然后抓取PDF但你应该是能够很容易地适应它。希望。

The code below just loop through a single folder, grabs images first and then PDFs but you should be able to adapt it pretty easily, hopefully.

//Folder that contains our sample files
var sourceFolder = System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "MergeTest");

//Final file that we're going to emit
var finalFile = System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "test.pdf");

//Create our final file, standard iText setup here
using (var fs = new FileStream(finalFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
    using (var doc = new Document()) {

        //Use a smart object copies to merge things
        using (var copy = new PdfSmartCopy(doc, fs)) {

            //Open the document for writing
            doc.Open();

            //Loop through each image in our test folder
            foreach (var img in System.IO.Directory.EnumerateFiles(sourceFolder, "*.jpg")) {

                //Convert the image to a byte array
                var imageAsPdf = ImageToPdf(img);

                //Bind a reader to that PDF
                using( var r = new PdfReader(imageAsPdf) ){

                    //Add that entire document to our final PDF
                    copy.AddDocument(r);
                }
            }

            //Loop through each PDF in our test folder
            foreach (var pdf in System.IO.Directory.EnumerateFiles(sourceFolder, "*.pdf")) {

                //Bind a reader to that PDF
                using (var r = new PdfReader(pdf)) {

                    //Add that entire document to our final PDF
                    copy.AddDocument(r);
                }
            }

            doc.Open();
        }
    }
}