Question

How to download .zip file format using c# code?

Here is the code, i am using to download. Just to highlight, If i download .txt file, it works fine. If i download .zip file, it downloads the .zip file but i can’t open this. It complains that .zip is in incorrect format. I have doubt in how i am writing back the file on local drive.

Help?

string ftpServerIP = FTPServer;
string ftpUserID = FTPUser;
string ftpPassword = FTPPwd;
FileInfo fileInf = new FileInfo(FileName);
string uri = "ftp://" + ftpServerIP + "/" + fileInf.Name;
FtpWebRequest reqFTP = (FtpWebRequest)FtpWebRequest.Create(uri); //new Uri("ftp://" + ftpServerIP + DestinationFolder + fileInf.Name));
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
reqFTP.EnableSsl = true;
reqFTP.KeepAlive = false;
reqFTP.UseBinary = true;
//reqFTP.UsePassive = true;
reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(AcceptAllCertifications);
//Stream strm = reqFTP.GetRequestStream();
StreamReader reader = new StreamReader(reqFTP.GetResponse().GetResponseStream());
StreamWriter writer = new StreamWriter(Path.Combine(FolderToWriteFiles, FileName), false);
writer.Write(reader.ReadToEnd());
return true; 

Answer 1

using System.Net;
// ...

new WebClient().DownloadFile("ftp://ftp.someurl.com/file.zip",
                             "C:\\downloadedFile.zip");

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Answer to the updated question:

The way you are saving the stream to disk is wrong. You are treating the stream as a character sequence, which corrupts the ZIP file in the process. Open a FileStream instead of a StreamWriter and copy the GetResponseStream() return value directly to that FileStream using something like my CopyStream function from here.