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File in use error after copying with WebClient to FTP

I download a file from a local ftp, with this code:
System.Net.WebClient oClientFTP = new System.Net.WebClient();
oClientFTP.Credentials = new System.Net.NetworkCredential("user", "password");
oClientFTP.DownloadFile("ftp://192.168.0.10/files/test.pdf","test.pdf");
oClientFTP.Dispose();
The file is copied correctly but is not released, anything I try to do tells me that the file is in use by another application. I tried using ProcessExplorer but it didn't solve the problem.
I also tried to copy the file to another file but the problem is the same.
How can I free the file after copying?

I solved it using a stream which I then write to file.
using (MemoryStream stream = new MemoryStream(oClientFTP.DownloadData(cFtp +cNomefile)))
{
using (FileStream outputFileStream = new FileStream(cNomefile, FileMode.Create))
{
stream.CopyTo(outputFileStream);
}
}

Download file directly to memory

I would like to load an excel file directly from an ftp site into a memory stream. Then I want to open the file in the FarPoint Spread control using the OpenExcel(Stream) method. My issue is I'm not sure if it's possible to download a file directly into memory. Anyone know if this is possible?

Yes, you can download a file from FTP to memory.
I think you can even pass the Stream from the FTP server to be processed by FarPoint.
WebRequest request = FtpWebRequest.Create("ftp://asd.com/file");
using (WebResponse response = request.GetResponse())
{
Stream responseStream = response.GetResponseStream();
OpenExcel(responseStream);
}
Using WebClient you can do nearly the same. Generally using WebClient is easier but gives you less configuration options and control (eg.: No timeout setting).
WebClient wc = new WebClient();
using (MemoryStream stream = new MemoryStream(wc.DownloadData("ftp://asd.com/file")))
{
OpenExcel(stream);
}

Take a look at WebClient.DownloadData. You should be able to download the file directory to memory and not write it to a file first.
This is untested, but something like:
var spreadSheetStream
= new MemoryStream(new WebClient().DownloadData(yourFilePath));
I'm not familiar with FarPoint though, to say whether or not the stream can be used directly with the OpenExcel method. Online examples show the method being used with a FileStream, but I'd assume any kind of Stream would be accepted.

Download file from URL to memory.
My answer does not exactly show, how to download a file for use in Excel, but shows how to create a generic-purpose in-memory byte array.
private static byte[] DownloadFile(string url)
{
byte[] result = null;
using (WebClient webClient = new WebClient())
{
result = webClient.DownloadData(url);
}
return result;
}

Decompressing a Zip file from a string

I'm fetching an object from couchbase where one of the fields has a file. The file is zipped and then encoded in base64.
How would I be able to take this string and decompress it back to the original file?
Then, if I'm using ASP.MVC 4 - How would I send it back to the browser as a downloadable file?
The original file is being created on a Linux system and decoded on a Windows system (C#).

You should use Convert.FromBase64String to get the bytes, then decompress, and then use Controller.File to have the client download the file. To decompress, you need to open the zip file using some sort of ZIP library. .NET 4.5's built-in ZipArchive class should work. Or you could use another library, both SharpZipLib and DotNetZip support reading from streams.
public ActionResult MyAction()
{
string base64String = // get from Linux system
byte[] zipBytes = Convert.FromBase64String(base64String);
using (var zipStream = new MemoryStream(zipBytes))
using (var zipArchive = new ZipArchive(zipStream))
{
var entry = zipArchive.Entries.Single();
string mimeType = MimeMapping.GetMimeMapping(entry.Name);
using (var decompressedStream = entry.Open())
return File(decompressedStream, mimeType);
}
}
You'll also need the MIME type of the file, you can use MimeMapping.GetMimeMapping to help you get that for most common types.

I've used SharpZipLib successfully for this type of task in the past.
For an example that's very close to what you need to do have a look here.
Basically, the steps should be something like this:
you get the compressed input as a string from the database
create a MemoryStream and write the string to it
seek back to the beginning of the memory stream
use the MemoryStream as an input to the SharpZipLib ZipFile class
follow the example provided above to unpack the contents of the ZipFile
Update
If the string contains only the zipped contents of the file (not a full Zip archive) then you can simply use the GZipStream class in .NET to unzip the contents. You can find a sample here. But the initial steps are the same as above (get string from db, write to memory stream, feed memory stream as input to the GZipStream to decompress).

Using webclient to download images from deployed website

i deployed a website on IIS running on localhost/xxx/xxx.aspx . On my WPF side , i download a textfile using webclient from the localhost server and save it at my wpf app folder
this is how i do it :
protected void DownloadData(string strFileUrlToDownload)
{
WebClient client = new WebClient();
byte[] myDataBuffer = client.DownloadData(strFileUrlToDownload);
MemoryStream storeStream = new MemoryStream();
storeStream.SetLength(myDataBuffer.Length);
storeStream.Write(myDataBuffer, 0 , (int)storeStream.Length);
storeStream.Flush();
string currentpath = System.IO.Directory.GetCurrentDirectory() + #"\Folder";
using (FileStream file = new FileStream(currentpath, FileMode.Create, System.IO.FileAccess.ReadWrite))
{
byte[] bytes = new byte[storeStream.Length];
storeStream.Read(bytes, 0, (int)storeStream.Length);
file.Write(myDataBuffer, 0, (int)storeStream.Length);
storeStream.Close();
}
//The below Getstring method to get data in raw format and manipulate it as per requirement
string download = Encoding.ASCII.GetString(myDataBuffer);
}
This is by writing btyes and saving them . But how do i download multiple image files and save it on my WPF app folder? I have a URL like this localhost/websitename/folder/designs/ , under this URL , there is many images , how do i download all of them ? and save it on WPF app folder?
Basically i want to download the contents of the folder whereby the contents are actually images.

First, the WebClient class already has a method for this. Use something like client.DownloadFile(remoteUrl, localFilePath).
See this link:
WebClient.DownloadFile Method (String, String)
Secondly, you will need to index the files you want to download on the server somehow. You can't just get a directory listing over HTTP and then loop through it. The web server will need to be configured to enable directory listing, or you will need a page to generate a directory listing. Then you will need to download the results of that page as a string using WebClient.DownloadString and parse it. A simple solution would be an aspx page that outputs a plaintext list of files in the directory you want to download.
Finally, in the code you posted you're saving every single file you download as a file named "Folder". You need to generate a unique filename for each file you want to download. When you're looping through the files you want to download, use something like:
string localFilePath = Path.Combine("MyDownloadFolder", imageName);
where imageName is a unique filename (with file extension) for that file.

Is there a way to download a file without Webclient in Silverlight?

I am in a situation where I have to download one file into Bytearray and make some changes in that byte array, also at the same time I have to download another large file and merge the first file into it with the modified bytes on the fly and play it using MediaElement.
Using Webclient I am able to download file but the webclient only gives me access to its dwonloaded bytearray when the file download is complete.
Is there a way to download the file and make modifications to the file's byte array on the fly in Silverlight.
I can not use Sockets, I can only download files from a Webserver.
Any help from you Gurus are appreciated

I can't see what is the problem with the Webclient.
You should copy the results of the WebClients in byte arrays.
Once every file has been downloaded, you can merge those byte arrays.
byte[] bytes;
public void DownloadFile()
{
WebClient webClient = new WebClient();
webClient.OpenReadCompleted += (s, e) =>
{
Stream stream = e.Result;
MemoryStream ms = new MemoryStream();
stream.CopyTo(ms);
bytes = ms.ToArray();
};
webClient.OpenReadAsync(new Uri("http://myurl.com/file.zip"), UriKind.Absolute);
}