Develop Reference

System.IO.IOException: Read-only file system at Interop.ThrowExceptionForIoErrno

When I deploy my changes to azure web app I am getting below exception :
enter image description here
But no local it's working fine.
I have check my file IsReadOnly=false or not.
Using a below code to achieve
var fileName = "myfilename.json";
var filePath = Path.Combine(Directory.GetCurrentDirectory(), fileName);
var configJSON = JsonConvert.SerializeObject(integrationsConfiguration);
cancellationToken.ThrowIfCancellationRequested();
FileInfo fileInfo = new FileInfo(fileName);
fileInfo.IsReadOnly = false;
using (FileStream fs = new FileStream(filePath, FileMode.Truncate, FileAccess.ReadWrite))
using (TextWriter writer = new StreamWriter(fs))
{
writer.WriteLine(configJSON);
}
return true;

c# files downloaded with httpwebrequest and cookies get corrupted

I am trying to make a program which is able to download files with URI(URL) using httpwebrequest and cookies(for credential information to keep login status).
I can download files with following code but files get corrupted after being downloaded.
when I download xlsx file(on the web page) into text file at local drive, I see some part of numbers and words from an original file in a corrupted file, therefore I assume I have reached to the right file.
however, when I download xlsx file(on the web page) in xlsx file at local drive, it seems like it fails to open saying
excel cannot open the file 'filename.xlsx' 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.
Is there any way I can keep fully original file content after I download?
I attach a part of result content as well.
private void btsDownload_Click(object sender, EventArgs e)
{
try
{
string filepath1 = #"PathAndNameofFile.txt";
string sTmpCookieString = GetGlobalCookies(webBrowser1.Url.AbsoluteUri);
HttpWebRequest fstRequest = (HttpWebRequest)WebRequest.Create(sLinkDwPage);
fstRequest.Method = "GET";
fstRequest.CookieContainer = new System.Net.CookieContainer();
fstRequest.CookieContainer.SetCookies(webBrowser1.Document.Url, sTmpCookieString);
HttpWebResponse fstResponse = (HttpWebResponse)fstRequest.GetResponse();
StreamReader sr = new StreamReader(fstResponse.GetResponseStream());
string sPageData = sr.ReadToEnd();
sr.Close();
string sViewState = ExtractInputHidden(sPageData, "__VIEWSTATE");
string sEventValidation = this.ExtractInputHidden(sPageData, "__EVENTVALIDATION");
string sUrl = ssItemLinkDwPage;
HttpWebRequest hwrRequest = (HttpWebRequest)WebRequest.Create(sUrl);
hwrRequest.Method = "POST";
string sPostData = "__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE=" + sViewState + "&__EVENTVALIDATION=" + sEventValidation + "&Name=test" + "&Button1=Button";
ASCIIEncoding encoding = new ASCIIEncoding();
byte[] bByteArray = encoding.GetBytes(sPostData);
hwrRequest.ContentType = "application/x-www-form-urlencoded";
Uri convertedURI = new Uri(ssDwPage);
hwrRequest.CookieContainer = new System.Net.CookieContainer();
hwrRequest.CookieContainer.SetCookies(convertedURI, sTmpCookieString);
hwrRequest.ContentLength = bByteArray.Length;
Stream sDataStream = hwrRequest.GetRequestStream();
sDataStream.Write(bByteArray, 0, bByteArray.Length);
sDataStream.Close();
using (WebResponse response = hwrRequest.GetResponse())
{
using (sDataStream = response.GetResponseStream())
{
StreamReader reader = new StreamReader(sDataStream);
{
string sResponseFromServer = reader.ReadToEnd();
FileStream fs = File.Open(filepath1, FileMode.OpenOrCreate, FileAccess.Write);
Byte[] info = encoding.GetBytes(sResponseFromServer);
fs.Write(info, 0, info.Length);
fs.Close();
reader.Close();
sDataStream.Close();
response.Close();
}
}
}
}
catch
{
MessageBox.Show("Error");
}
}

StreamReader is for dealing with text data. Using it corrupts your binary data(excel file).
Write sDataStream directly to file. For ex.
sDataStream.CopyTo(fs)
PS: I prepared a test case (using similar logic) to show how your code doesn't work
var binaryData = new byte[] { 128,255 };
var sr = new StreamReader(new MemoryStream(binaryData));
var str3 = sr.ReadToEnd();
var newData = new ASCIIEncoding().GetBytes(str3); //<-- 63,63
Just compare binaryData with newData

Decompressing a zipfile into memory stream - C#

I have written code to store the encoded string of zip file into temp path and now I want to store the encoded zipfile string to memorystream instead of temp path. Can someone please help me how to read the stream and pass it as a string to ZipFile class...I am using DOTNETZIP library to unpack password protested file.
Please see below my code.
string tempPath = Path.GetTempPath();
foreach (ActivityMimeAttachment a in attachments.Entities)
{
if (a.FileName.EndsWith(".zip", StringComparison.OrdinalIgnoreCase))
{
string strcontent = a.Body;
byte[] filecontent = Convert.FromBase64String(strcontent); // unpack the base-64 to a blob
File.WriteAllBytes(tempPath + a.FileName, filecontent); // Working code creates a zip file
string attachmentfile = tempPath + a.FileName;
using (ZipFile zip = new ZipFile(attachmentfile))
{
foreach (ZipEntry entry in zip.Entries)
{
if ((entry.FileName.EndsWith(".xml", StringComparison.OrdinalIgnoreCase)) ||
(entry.FileName.EndsWith(".pdf", StringComparison.OrdinalIgnoreCase)))
{
entry.ExtractWithPassword(tempPath, "password");
FileStream inFile;
byte[] binaryData;
string file = tempPath + entry.FileName;
inFile = new FileStream(file, FileMode.Open, FileAccess.Read);
binaryData = new Byte[inFile.Length];
long bytesRead = inFile.Read(binaryData, 0,
(int)inFile.Length);
inFile.Close();

You'll want to convert your file content to a memory stream (Stream filestream = new MemoryStream(filecontent)) then use ZipFile.Read(fileStream). Then use a StreamReader to get the contents out as a string. So try something like this (note it's untested):
string myString;
byte[] filecontent = Convert.FromBase64String(strcontent);
using (var filestream = new MemoryStream(filecontent))
{
using (ZipFile zip = ZipFile.Read(filestream))
{
foreach (ZipEntry entry in zip.Entries)
{
if ((entry.FileName.EndsWith(".xml", StringComparison.OrdinalIgnoreCase)) ||
(entry.FileName.EndsWith(".pdf", StringComparison.OrdinalIgnoreCase)))
{
using (var ms = new MemoryStream())
{
entry.ExtractWithPassword(ms, "password");
ms.Position = 0;
var sr = new StreamReader(ms);
myString = sr.ReadToEnd();
}
...
If the results should be a base64 string, do this:
entry.ExtractWithPassword(ms, "password");
ms.Position = 0;
myString = Convert.ToBase64String(ms.ToArray());
You may or may not have to reset the stream position, but it's good practice to.
Now you can use the results as a string without having to write to a file first.

Prompt for Saving File to Disk

Actually, I have saved a file in BinaryData in Sql and now I am able to download that file by converting the BinaryData into Bytes.
My code is :
object value = (sender as DevExpress.Web.ASPxGridView.ASPxGridView).GetRowValues(e.VisibleIndex, "ID");
Int64 FileID = Convert.ToInt64(value);
var filedata = (from xx in VDC.SURVEY_QUESTION_REPLIES
where xx.ID == FileID
select xx).FirstOrDefault();
string fileextension = filedata.FILE_EXTENSION.ToString();
string fileName = filedata.ANSWER_TEXT.ToString() + fileextension;
string DocumentName = null;
FileStream FStream = null;
BinaryWriter BWriter = null;
byte[] Binary = null;
const int ChunkSize = 100;
int SizeToWrite = 0;
MemoryStream MStream = null;
DocumentName = fileName;
FStream = new FileStream(#"c:\\" + DocumentName, FileMode.OpenOrCreate, FileAccess.Write);
BWriter = new BinaryWriter(FStream);
Binary = (filedata.FILE_DATA) as byte[];
SizeToWrite = ChunkSize;
MStream = new MemoryStream(Binary);
for (int i = 0; i < Binary.GetUpperBound(0) - 1; i = i + ChunkSize)
{
if (i + ChunkSize >= Binary.Length) SizeToWrite = Binary.Length - i;
byte[] Chunk = new byte[SizeToWrite];
MStream.Read(Chunk, 0, SizeToWrite);
BWriter.Write(Chunk);
BWriter.Flush();
}
BWriter.Close();
FStream.Close();
FStream.Dispose();
System.Diagnostics.Process.Start(#"c:\" + DocumentName);
and it is directly saving the file to the location C Drive.
Now,My Requirement is that,I need to get a Prompt for saving that file and user need to select the location of saving.
Is that Possible ?

You create a filestream with a fixed location here:
FStream = new FileStream(#"c:\\" + DocumentName, FileMode.OpenOrCreate, FileAccess.Write);
What you would have to do is something like this:
var dialog = new SaveFileDialog();
if (dialog.ShowDialog() == DialogResult.OK)
{
FStream = new FileStream(dialog.FileName, FileMode.OpenOrCreate, FileAccess.Write);
// put the rest of your file saving code here
}
Remember to import the Forms namespace
using System.Windows.Forms;

If its Forms app You can use SaveFileDialog class

it is possible,
you can use a saveFileDialog that you create in your designer and call the "show" method to open that dialog :
private void button1_Click(object sender, System.EventArgs e)
{
Stream myStream ;
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*" ;
saveFileDialog1.FilterIndex = 2 ;
saveFileDialog1.RestoreDirectory = true ;
if(saveFileDialog1.ShowDialog() == DialogResult.OK)
{
if((myStream = saveFileDialog1.OpenFile()) != null)
{
// Code to write the stream goes here.
myStream.Close();
}
}
}
Source : http://msdn.microsoft.com/en-gb/library/system.windows.forms.savefiledialog.aspx

I see that you use web components of DevExpress, so assuming that you want to send the stream to response for the client to save the file.
If it is an ASP.NET MVC application, you can return FileContentResult as action result directly. Otherwise, you might use the following sample adapting into your code
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=" + DocumentName);
MStream.WriteTo(Response.OutputStream);
Depending on user's browser settings, save file dialog might be shown to the user.

c# Replace openfileDialog to a none gui stream

I am trying to separate the MIME gui from the code i need. I am almost there just one more gui element i dont know how to replace. This element is the openfiledialog. Here a code snippet.
Program.cs
var sfd = new OpenFileDialog();
sfd.FileName = "C:\\eml\\" + validOutputFilename;
try
{
var writer = new MimeMessageWriter();
using (var fs = sfd.OpenFile()) writer.Write(message, fs);
}
catch (Exception ex)
{
//ignore
// need to log
}
message is an IMessage. A class created to store the information about an eml file. The open file dialog is allowing you to put in the file name with an eml extension and that is all. write.Write expects an IMessage and a stream. Inside writer.Write the file is being written The only part of the file that uses this code is when the file itself is writen at the end and write out any attachments. Here are those code snippets.
*MimeMessageWriter
-the attachment uses it here
var embeddedMessage = attachment.OpenAsMessage();
var messageWriter = new MimeMessageWriter();
var msgStream = new MemoryStream();
messageWriter.Write(embeddedMessage, msgStream);
var messageAttachment = ew DotNetOpenMail.FileAttachment(msgStream.ToArray());
messageAttachment.ContentType = "message/rfc822";
messageAttachment.FileName = filename + ".eml";
outMessage.AddMixedAttachment(messageAttachment);
-write out the file part of the file
using (var sw = new StreamWriter(stream))
sw.Write(outMessage.ToDataString());
I want to replace openFileDialog with something that will allow me to pass the filename to write out file in the MimeMessageWriter

Replace
using (var fs = sfd.OpenFile()) writer.Write(message, fs);
with
string fileName = #"c:\eml\myAttachment.eml";
using ( FileStream fs = new FileStream( fileName, FileMode.CreateNew ) )
{
writer.Write( message, fs )
}
See also: http://msdn.microsoft.com/de-de/library/47ek66wy.aspx