使用 iTextSharp 问题创建和下载 (HTML 到) PDF

Question

我可以毫无问题地成功创建/生成PDF文件。但是当我尝试在生成后下载它时，执行被重定向到，

void Application_Error(object sender, EventArgs e)
{
    // Code that runs when an unhandled error occurs
}

在按钮的单击事件中，我创建了按预期工作的PDF文件，如下所示。

using System.Data;
using iTextSharp.text;
using iTextSharp.text.html.simpleparser;
using iTextSharp.text.pdf;
using System.Net;
protected void Button2_Click(object sender, EventArgs e)
{
    try
    {
        string htmlContent = "<div> PDF Code </div>"; // you html code (for example table from your page)
        Document document = new Document();
        string FileName = Guid.NewGuid().ToString();
        PdfWriter.GetInstance(document, new FileStream("C:\...\...\PDF\" + FileName + ".pdf", FileMode.Create));
        document.Open();
        HTMLWorker worker = new HTMLWorker(document);
        worker.Parse(new StringReader(htmlContent));
        document.Close();
         //To download same PDF I write below code
        Response.Clear();
        string pdfPath = Server.MapPath(@"~PDF" + FileName + ".pdf");
        WebClient client = new WebClient();
        Byte[] buffer = client.DownloadData(pdfPath);
        Response.ContentType = "application/pdf";
        Response.AddHeader("content-length", buffer.Length.ToString());
        Response.BinaryWrite(buffer);
        Response.Flush();
        HttpContext.Current.ApplicationInstance.CompleteRequest();
        ////Response.End();
    }
    catch (Exception ex)
    {
        Response.Write(ex.Message.ToString());
    }
}

此代码不会引发任何异常，而是重定向到上面的提及方法。请帮忙。

我想要的是按钮的点击事件，我想生成 PDF 并下载相同的内容。尝试了很多事情，但没有成功。

Answer 1

[...]CompleteRequest（） 方法在被调用时不会结束执行。因此，如果这真的是您想要做的，那么Response.Redirect（string）将是您要走的路。

CompleteRequest（）

只是绕过了 Response.End（） 方法，该方法生成了你提到的 ThreadAbortException，但至关重要的是 CompleteRequest（） 刷新了响应缓冲区。这意味着 HTTP 302 重定向响应将发送到您调用 CompleteRequest（） 的行的浏览器，这使您有机会在将响应发送给用户后执行不影响响应的操作。[...]

源

Answer 2

我最近能够通过向事件添加以下代码来解决我的问题page_load()，

protected void Page_Load(object sender, EventArgs e)
        {
            ScriptManager scriptManager = ScriptManager.GetCurrent(this.Page);
            scriptManager.RegisterPostBackControl(this.Button2);
             //where button2 is the button by which pdf is generated and post back happens.          
        }

下面的新代码工作绝对正常。

protected void Button2_Click(object sender, EventArgs e)
        {
            try
            {
                string htmlContent = "<div> PDF Code </div>"; // you html code (for example table from your page)
                Document document = new Document();
                string FileName = Guid.NewGuid().ToString();
                PdfWriter.GetInstance(document, new FileStream("C:\...\...\PDF\" + FileName + ".pdf", FileMode.Create));
                document.Open();
                HTMLWorker worker = new HTMLWorker(document);
                worker.Parse(new StringReader(htmlContent));
                document.Close();
                Response.ContentType = "application/pdf";
                Response.AppendHeader("Content-Disposition", "attachment; filename=" + FileName + ".pdf");
                Response.TransmitFile(Server.MapPath(@"~PDF" + FileName + ".pdf"));
                Response.End();
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message.ToString());
            }
        }

Answer 3

在

点击事件中添加此代码

Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment;filename=Panel.pdf");
Response.Cache.SetCacheability(HttpCacheability.NoCache);
StringWriter sw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(sw);
pnlPerson.RenderControl(hw);
StringReader sr = new StringReader(sw.ToString());
Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 100f, 0f);
HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
pdfDoc.Open();
htmlparser.Parse(sr);
pdfDoc.Close();
Response.Write(pdfDoc);
Response.End();