convert C# httpwebrequest to vb.net - c#

i have this C# code for download xlsx document from url
var request = (HttpWebRequest)WebRequest.Create("url to xlsx file");
request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
request.Headers[HttpRequestHeader.AcceptEncoding] = "gzip,deflate";
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
using (var output = File.Create("H:\\doc.xlsx"))
{
stream.CopyTo(output);
}
my target programming language is VB.net so i changed C# to vb like below
Dim request As HttpWebRequest = WebRequest.Create("url to xlsx file")
request.AutomaticDecompression = DecompressionMethods.GZip Or DecompressionMethods.Deflate
request.Headers(HttpRequestHeader.AcceptEncoding) = "gzip,deflate"
Dim response As WebResponse = request.GetResponse()
Dim stream As Stream = response.GetResponseStream()
Dim output As FileStream = File.Create("H:\doc.xlsx")
stream.CopyTo(output)
xlsx file that is downloaded by VB is corrupted and unreadable but C# works well
what is the mistake?

Try including the using statements: It is possible the whole content has not been flushed to the output so you get the corrupt message.
Using response = request.GetResponse()
Using stream = response.GetResponseStream()
Using output = File.Create("H:\doc.xlsx")
stream.CopyTo(output)
End Using
End Using
End Using
The using block will make sure to dispose of the objects, which you should be doing regardless of the issue of ending with a corrupted file, and it will also call Close() method on the underlying to stream and any data previously written to the buffer will be copied to the file before the file stream is closed,

Related

Convert docx stream to pdf directly

I need to convert any file coming from web response into .pdf format, I'm currently getting it word docx file format from the URL and saving it into memory stream so i can later insert it in it's designated library.
The problem I'm facing now is that I'm saving my docx files directly into .pdf by putting an extension at the end which obviously ends up not opening the file later, So i'm trying to convert my memory stream into pdf directly .
Here is my piece of code that i tried to convert the the stream to .pdf but it looks like the file isn't getting converted correctly.
private Stream DownloadFromUrl(string url)
{
var webRequest = WebRequest.Create(url);
webRequest.Credentials = CredentialCache.DefaultNetworkCredentials;
webRequest.PreAuthenticate = true;
webRequest.UseDefaultCredentials = true;
//EventLogUtility.LogInformationMessage(DocumentURL);
string message = string.Empty;
using (Stream outputStream = new MemoryStream())
{
using (var response = webRequest.GetResponse())
{
using (var content = response.GetResponseStream())
{
var memory = new MemoryStream();
content.CopyTo(memory);
Document doc = new Document(memory);
doc.Save(memory, SaveFormat.Pdf);
return memory;
}
}
}
}
If the content in the stream is actually in the Microsoft Word file format (and not just plain text), then you need to map the format to the file format for PDF. I know there is a 'Print to PDF' function available in Word, you could try looking into that.

xlsx excel cannot open the file because the file format or file extension is not valid - c#

I am trying to create an excel file from the response of SSRS reporting server, on front-end I successfully able to download an excel file but when I open it I get the error.
xlsx excel cannot open the file because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file.
Here is the code:
HttpWebRequest req =
(HttpWebRequest)WebRequest.Create(sTargetURL);
req.PreAuthenticate = true;
req.Credentials = new System.Net.NetworkCredential(strReportUser, strReportUserPW, strReportUserDomain);
HttpWebResponse HttpWResp = (HttpWebResponse)req.GetResponse();
Stream fStream = HttpWResp.GetResponseStream();
//Now turn around and send this as the response..
byte[] fileBytes = ReadFully(fStream);
string fileToAttach = Convert.ToBase64String(fileBytes);
HttpWResp.Close();
Stream stream = new MemoryStream(fileBytes);
result.Content = fileToAttach;
result.ContentType = "application/vnd.openxmlformats-
officedocument.spreadsheetml.sheet";
result.FileName = fileName + ".xlsx";
result.result = true;
return result;
Any help would be appreciated.
Assuming response is some kind of HTTP response object that eventually gets sent to the browser, and that you have the actual Excel file contents in fStream, the problem is you are sending the Base64'd version of the file as the contents (which Excel is not going to understand):
Stream fStream = HttpWResp.GetResponseStream();
byte[] fileBytes = ReadFully(fStream);
string fileToAttach = Convert.ToBase64String(fileBytes);
result.Content = fileToAttach;
Since I can't see what response is, all I can say is you need to leave the file contents intact.
If you want to send the raw bytes, you could do:
Stream fStream = HttpWResp.GetResponseStream();
byte[] fileBytes = ReadFully(fStream);
result.Content = fileBytes;
If your response can handle a Stream, that would be the ideal way (then you don't have to convert it back and forth between a stream and byte data).
If result.Content has to be a string, then you have to worry about which encoding to use, and it'll look something like:
Stream fStream = HttpWResp.GetResponseStream();
byte[] fileBytes = ReadFully(fStream);
result.Content = Encoding.UTF8.GetString(fileBytes);
It wouldn't surprise me if Excel needs to be encoded as UTF-16 (Microsoft uses it quite heavily internally).

Uploading files to ftp folder having special characters in name

I am trying to upload a file on FTP folder, but getting the following error.
The remote server returned an error: (550) File unavailable (e.g.,
file not found, no access)
I am using the following sample to test this:
// Get the object used to communicate with the server.
string path = HttpUtility.UrlEncode("ftp://host:port//01-03-2017/John, Doe S. M.D/file.wav");
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(path);
request.Method = WebRequestMethods.Ftp.UploadFile;
// This example assumes the FTP site uses anonymous logon.
request.Credentials = new NetworkCredential("user", "password");
// Copy the contents of the file to the request stream.
StreamReader sourceStream = new StreamReader(#"localpath\example.wav");
byte[] fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());
sourceStream.Close();
request.ContentLength = fileContents.Length;
Stream requestStream = request.GetRequestStream();
requestStream.Write(fileContents, 0, fileContents.Length);
requestStream.Close();
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
Console.WriteLine("Upload File Complete, status {0}", response.StatusDescription);
response.Close();
I am able to upload files on the parent folder 01-03-2017 but not in the target folder ROLLINS, SETH S. M.D which clearly has special characters in it.
I am able to upload files using FileZilla
I have tried to HttpUtility.UrlEncode but that did n't help
Thanks for your time and help.
You need to encode the spaces (and maybe commas) in the URL path, like:
string path =
"ftp://host:port/01-03-2017/" +
HttpUtility.UrlEncode("John, Doe S. M.D") + "/file.wav";
Effectively, you get:
ftp://host:port/01-03-2017/John%2c+Doe+S.+M.D/file.wav
Use something like this:
string path = HttpUtility.UrlEncode("ftp://96.31.95.118:2121//01-03-2017//ROLLINS, SETH S. M.D//30542_3117.wav");
or You can form a Uri using the following code and pass it webrequest.
var path = new Uri("ftp://96.31.95.118:2121//01-03-2017//ROLLINS, SETH S. M.D//30542_3117.wav");
The code works on a C# console application but did not work in Web Api Action. I could not manage to find the reason.
So I have used a free library for the same.
Posting the sample code from one of the examples available here:
So i have used FluentFtp libary available through Nuget.
using System;
using System.IO;
using System.Net;
using FluentFTP;
namespace Examples {
public class OpenWriteExample {
public static void OpenWrite() {
using (FtpClient conn = new FtpClient()) {
conn.Host = "localhost";
conn.Credentials = new NetworkCredential("ftptest", "ftptest");
using (Stream ostream = conn.OpenWrite("01-03-2017/John, Doe S. M.D/file.wav")) {
try {
// istream.Position is incremented accordingly to the writes you perform
}
finally {
ostream.Close();
}
}
}
}
}
}
Again, if the file is a binary file, StreamReader should not be used as explained here.

Download files using ftp in c# [duplicate]

This question already has answers here:
Upload file and download file from FTP
(3 answers)
Closed 4 years ago.
i need to change the logic in an old system and im trying to get the downloading file to work, any ideas? i need to download the files using ftp in c# this is the code i found but i need to get that into a file instead of a stream
// Get the object used to communicate with the server.
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://192.168.1.52/Odt/"+fileName+".dat");
request.Method = WebRequestMethods.Ftp.DownloadFile;
// This example assumes the FTP site uses anonymous logon.
request.Credentials = new NetworkCredential ("anonymous","janeDoe#contoso.com");
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
Stream responseStream = response.GetResponseStream();
StreamReader reader = new StreamReader(responseStream);
Console.WriteLine(reader.ReadToEnd());
Console.WriteLine("Download Complete, status {0}", response.StatusDescription);
reader.Close();
response.Close();
The suggestion from commenter Ron Beyer isn't bad, but because it involves decoding and re-encoding the text, there is a risk of data loss.
You can download the file verbatim by simply copying the request response stream to a file directly. That would look something like this:
// Some file name, initialized however you like
string fileName = ...;
using (Stream responseStream = response.GetResponseStream())
using (Stream fileStream = File.OpenWrite(filename))
{
responseStream.CopyTo(fileStream);
}
Console.WriteLine("Download Complete, status {0}", response.StatusDescription);
response.Close();

Update CSV header Using CsvReader

I have a CSV file that I grab & convert it into Stream. I need a way to modify header without converting stream to string. Is there a way around?
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream resStream = response.GetResponseStream();
//need to update stream here & continue with the CSV reader
using (CsvReader csv = new CsvReader(new StreamReader(resStream), true))
{
//other code
}
Derive your own class from StreamReader and override the function you use for reading it, inserting the proper behavior.

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