如何使用ITextSharp和C# Blazor下载编辑过的PDF

dotnet --version

dotnet new blazorserver -n MyPdfApp

dotnet add package iTextSharp

<button @onclick="DownloadAndEditPdf">下载和编辑PDF</button>

using iTextSharp.text;
using iTextSharp.text.pdf;
using System.IO;

public class IndexModel : ComponentBase
{
    private void DownloadAndEditPdf()
    {
        // 创建一个新的PDF文档
        Document document = new Document();
        PdfWriter writer = PdfWriter.GetInstance(document, new FileStream("edited.pdf", FileMode.Create));
        document.Open();

        // 添加内容到PDF文档
        document.Add(new Paragraph("这是一个编辑过的PDF文档"));

        // 关闭PDF文档
        document.Close();

        // 下载PDF文档
        byte[] fileBytes = File.ReadAllBytes("edited.pdf");
        string fileName = "edited.pdf";
        string contentType = "application/pdf";
        DownloadFile(fileBytes, fileName, contentType);
    }

    private void DownloadFile(byte[] fileBytes, string fileName, string contentType)
    {
        MemoryStream ms = new MemoryStream(fileBytes);
        HttpContext.Response.Clear();
        HttpContext.Response.ContentType = contentType;
        HttpContext.Response.Headers.Add("content-disposition", "attachment;filename=" + fileName);
        HttpContext.Response.Body.WriteAsync(ms.ToArray());
        HttpContext.Response.CompleteAsync();
    }
}

dotnet run