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如何在C#[关闭]中从外部站点的url读取PDF文件

pdf-reader url-routing asp.net c#

Najat Al-Naamani · 技术社区 · 7 年前

我想能够下载一个pdf,是由一个路由url(外部网站)在我的asp。net应用程序。有办法吗?

当前情况: 路由url位于公司内部网站(joomla网站) http://example/sites/index.php/2011-10-30-12-29-04/finish/11/1234 此链接将用户重定向到pdf文件我需要使用路由url在我的应用程序(PdfReader)中获取此pdf。

更新#1:

我按照你的建议对代码做了一些更改(我在原始问题中添加了它),只是需要将内容流传递给我的pdfReader。然而,它仍然告诉我下载失败。。

更新#2: 现在问题解决了,我必须按如下方式传递contentstream Dim pdfReader作为新的pdfReader(isp:=内容流)

非常感谢。。

   Public Async Function GetPDFFromCompanyWebsite() As Task(Of HttpResponseMessage)

    Using client As HttpClient = New HttpClient()
        Dim msg As HttpResponseMessage = Await client.GetAsync("http://example/sites/index.php/2011-10-30-12-29-04/finish/4/4088")
        If msg.IsSuccessStatusCode Then


            Dim contentStream = Await msg.Content.ReadAsStreamAsync()

            Dim pdfReader As New PdfReader(isp:=contentStream)
            Dim MST As MemoryStream = New MemoryStream()
            Dim pdfStamper As New PdfStamper(pdfReader, MST)
            For pageIndex As Integer = 1 To pdfReader.NumberOfPages
                Dim pageRectangle As Rectangle = pdfReader.GetPageSizeWithRotation(pageIndex)
                Dim pdfData As PdfContentByte = pdfStamper.GetOverContent(pageIndex)

                pdfData.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA_BOLD, BaseFont.CP1252, BaseFont.NOT_EMBEDDED), 40)
                Dim graphicsState As New PdfGState()


                graphicsState.FillOpacity = 0.1F
                pdfData.SetGState(graphicsState)

                pdfData.SetColorFill(BaseColor.BLUE)

                Dim bf As BaseFont = BaseFont.CreateFont(BaseFont.TIMES_ROMAN, BaseFont.CP1252, BaseFont.NOT_EMBEDDED)

                pdfData.SetFontAndSize(bf, pageRectangle.Width / 25)
                pdfData.BeginText()
                pdfData.SetFlatness(1000)

                Dim windowsuser As String = User.Identity.Name.Substring(4)
                windowsuser = windowsuser + "        " + windowsuser + "        " + windowsuser + "        " + windowsuser + "        " + windowsuser + "        " + windowsuser + "        " + windowsuser
                '    pdfData.ShowTextAligned(Element.ALIGN_BOTTOM, User.Identity.Name, 100, 100, 45)
                Response.Write("width:height: " + pageRectangle.Width.ToString + " / " + pageRectangle.Height.ToString)
                pdfData.ShowTextAligned(Element.ALIGN_CENTER, windowsuser, pageRectangle.Width / 2, pageRectangle.Height / 2, 45)
                pdfData.ShowTextAligned(Element.ALIGN_CENTER, windowsuser, pageRectangle.Width / 4, pageRectangle.Height - (pageRectangle.Height / 4), 45)
                pdfData.ShowTextAligned(Element.ALIGN_CENTER, windowsuser, pageRectangle.Width - (pageRectangle.Width / 4), pageRectangle.Height / 4, 45)
                pdfData.ShowTextAligned(Element.ALIGN_CENTER, windowsuser, (3 * pageRectangle.Width) / 8, pageRectangle.Height - ((3 * pageRectangle.Height) / 8), 45)
                pdfData.ShowTextAligned(Element.ALIGN_CENTER, windowsuser, pageRectangle.Width - ((3 * pageRectangle.Width) / 8), (3 * pageRectangle.Height) / 8, 45)




                pdfData.EndText()

            Next
            pdfStamper.Close()
            Dim bytesInStream As Byte() = MST.ToArray()

            MST.Close()

            Response.Clear()
            Response.ClearContent()
            Response.ClearHeaders()
            Response.ContentType = "application/pdf"
            Response.AddHeader("content-disposition", "attachment;filename=File.pdf")
            Response.BufferOutput = True
            Response.Cache.SetCacheability(HttpCacheability.NoCache)
            Response.BinaryWrite(bytesInStream)
            Response.End()
            Response.Close()

            '        End Using
        End If

        Return msg
    End Using
End Function

1 回复 | 直到 7 年前

Kunal Mukherjee 7 年前

尝试使用C#中的HttpClient类向您公司的网站发出GET请求。你可以沿着这条路线做一些事情。

using System.Net.Http;
using System.IO;

public async Task<HttpResponseMessage> GetPDFFromCompanyWebsite()
{
string currentDirectory = System.Web.Hosting.HostingEnvironment.MapPath("~");
string filePath = Path.Combine(currentDirectory, "App_Data", "someDocument.pdf");

using(HttpClient client = new HttpClient())
{
    HttpResponseMessage msg = await client.GetAsync($"http://example/sites/index.php/2011-10-30-12-29-04/finish/11/1234");

    if(msg.IsSuccessStatusCode)
    {
     using(var file = File.Create(filePath))
     { 
       // create a new file to write to
       var contentStream = await msg.Content.ReadAsStreamAsync(); // get the actual content stream
       await contentStream.CopyToAsync(file); // copy that stream to the file stream
       await file.FlushAsync(); // flush back to disk before disposing
     }
   }
  return msg;
} }