Display (Show) PDF file from FTP Server using C# and VB.Net in ASP.Net

Hi namojainashis...,

Refer below sample code.

HTML

<asp:Button Text="View" runat="server" OnClick="FTPViewPDF" />

Namespaces

C#

using System.IO;
using System.Net;

VB.Net

Imports System.IO
Imports System.Net

Code

C#

protected void FTPViewPDF(object sender, EventArgs e)
{
    string fileName = (sender as LinkButton).CommandArgument;

    //FTP Server URL.
    string ftp = "ftp://yourserver.com/";

    //FTP Folder name. Leave blank if you want to Download file from root folder.
    string ftpFolder = "Uploads/";

    try
    {
        //Create FTP Request.
        FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftp + ftpFolder + fileName);
        request.Method = WebRequestMethods.Ftp.DownloadFile;

        //Enter FTP Server credentials.
        request.Credentials = new NetworkCredential("Username", "Password");
        request.UsePassive = true;
        request.UseBinary = true;
        request.EnableSsl = false;

        //Fetch the Response and read it into a MemoryStream object.
        FtpWebResponse webResponse = (FtpWebResponse)request.GetResponse();
        using (MemoryStream stream = new MemoryStream())
        {
            //Download the File.
            CopyStream(webResponse.GetResponseStream(), stream);
            byte[] bytes = stream.ToArray();

            Response.Cache.SetCacheability(HttpCacheability.NoCache);
            Response.ContentType = "application/pdf";
            Response.BinaryWrite(bytes);
            Response.Flush();
            Response.End();
        }
    }
    catch (WebException ex)
    {
        throw new Exception((ex.Response as FtpWebResponse).StatusDescription);
    }
}

public static void CopyStream(Stream input, Stream output)
{
    byte[] buffer = new byte[4096];
    while (true)
    {
        int read = input.Read(buffer, 0, buffer.Length);
        if (read <= 0)
        {
            return;
        }
        output.Write(buffer, 0, read);
    }
}

VB.Net

Protected Sub FTPViewPDF(ByVal sender As Object, ByVal e As EventArgs)
    Dim fileName As String = (TryCast(sender, LinkButton)).CommandArgument
    Dim ftp As String = "ftp://yourserver.com/"
    Dim ftpFolder As String = "Uploads/"

    Try
        Dim request As FtpWebRequest = CType(WebRequest.Create(ftp & ftpFolder & fileName), FtpWebRequest)
        request.Method = WebRequestMethods.Ftp.DownloadFile
        request.Credentials = New NetworkCredential("Username", "Password")
        request.UsePassive = True
        request.UseBinary = True
        request.EnableSsl = False
        Dim webResponse As FtpWebResponse = CType(request.GetResponse(), FtpWebResponse)

        Using stream As MemoryStream = New MemoryStream()
            CopyStream(webResponse.GetResponseStream(), stream)
            Dim bytes As Byte() = stream.ToArray()
            Response.Cache.SetCacheability(HttpCacheability.NoCache)
            Response.ContentType = "application/pdf"
            Response.BinaryWrite(bytes)
            Response.Flush()
            Response.End()
        End Using

    Catch ex As WebException
        Throw New Exception((TryCast(ex.Response, FtpWebResponse)).StatusDescription)
    End Try
End Sub

Public Shared Sub CopyStream(ByVal input As Stream, ByVal output As Stream)
    Dim buffer As Byte() = New Byte(4095) {}
    While True
        Dim read As Integer = input.Read(buffer, 0, buffer.Length)
        If read <= 0 Then
            Return
        End If
        output.Write(buffer, 0, read)
    End While
End Sub