Develop Reference

How can I write data to the App_Data folder in ASP.NET MVC?

I can write data to the App_Data folder in my ASP.NET Web API app like so:
string appDataFolder = HttpContext.Current.Server.MapPath("~/App_Data/");
var htmlStr = // method that returns html as a string
string htmlFilename = "platypus.html";
string fullPath = Path.Combine(appDataFolder, htmlFilename);
File.WriteAllText(fullPath, htmlStr);
I want to do something similar in an ASP.NET MVC app (the data is different - a PDF file instead of an html file), but "File" is not recognized. I try this:
using (var ms = new MemoryStream())
. . .
var bytes = ms.ToArray();
string appDataFolder = AppDomain.CurrentDomain.GetData("DataDirectory").ToString();
string pdfFilename = "test.pdf";
string fullPath = Path.Combine(appDataFolder, pdfFilename);
File.WriteAllText(fullPath, bytes);
...but get, "'System.Web.Mvc.Controller.File(byte[], string)' is a 'method', which is not valid in the given context'"
In the first place, I don't think my code is what the err msg seems to indicate it is, but nevertheless it's not accepted, so: how can I write data to the App_Data folder in ASP.NET MVC?

It looks like a namespace collision. The compiler is grabbing File from a different namespace than is expected. The File class that should make this work is in the System.IO namespace and not the System.Web.Mvc.Controller namespace.
This can be fixed by explicitly specifying the correct namespace when calling File.WriteAllText():
System.IO.File.WriteAllText(fullPath, bytes);

Razor MVC Controller Download file

I have a controller like the code below and I would like to know how to call this using Razor
because #Url.Action("GetFileFromDisk") does not work as expected it just crashes. If it is possible could you point out my mistake here? Or maybe suggest a better way to force on click to download the file
public FilePathResult GetFileFromDisk()
{
string path = AppDomain.CurrentDomain.BaseDirectory + "uploads/";
string fileName = "test.txt";
return File(path + fileName, "text/plain", "test.txt");
}
Thanks in advance.
Update
the Error message I get is
The webpage at http://mypage/Support/GetFileFromDisk might be temporarily down or it may have moved permanently to a new web address.
Error code: ERR_INVALID_RESPONSE`

To force a file download, you should probably use octet-stream. It's up to the client (browser) to determine whether to download or display content, but octet-stream is normally downloaded, no matter what. You should also use Path.Combine instead of manually concatenating the filename with the path.
public FilePathResult GetFileFromDisk()
{
string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "uploads/");
string fileName = "test.txt";
return File(Path.Combine(path,fileName), "application/octet-stream", "test.txt");
}
edit, now that you've given the actual error:
This "might be temporarily down" message means no route could be found in your application that matches the given URL. There's probably something wrong with your URL.
Tips:
Check if you can reach actions that are sibling to "GetFileFromDisk" using the same URL pattern.
Review your routes.
Install Glimpse so you can debug your routes.

i think you should be using FileResult if you return File insted of FilePathResult
or use the FilePathResult as return
public FilePathResult GetFileFromDisk()
{
string path = AppDomain.CurrentDomain.BaseDirectory + "uploads/";
string fileName = "test.txt";
return new FilePathResult(Path.Combine(path, fileName), System.Net.Mime.MediaTypeNames.Application.Octet);
}

File is always named with the Path

My File is always named like the path and my additional informations i want to have in the Filename but why is it like that?
The Path should be the chosen folder and i want to create a folder then, how can i add a folder than and say + that folder path?
The file is also always created 1 layer above the one i want. For example: C:\Test but the file is saved then in C:\ instead of C:\Test.
public static string path= string.Empty;
string fileName = DateTime.Now.ToString("yyyy.MM.dd") + "test.txt";
try
{
FileStream fs = new FileStream(path + fileName, FileMode.CreateNew, FileAccess.ReadWrite);
StreamWriter sw= new StreamWriter(fs);
sw.WriteLine("Test and so on ..");
}
catch(Exception ex) { }

Rather than using string concatenation, use Path.Combine. Aside from anything else, that will be portable if you ever want to use Mono, too.
Oh, and there are simpler ways to create a text file too:
using (var writer = File.CreateText(Path.Combine(path, fileName))
{
writer.WriteLine(...);
}
Finally, I'd strongly advise using - instead of . in your filename, so that anything which looks at the first . and expects the rest to be an extension doesn't get confused:
string fileName = DateTime.ToString("yyyy-MM-dd") + "-test.txt";

c# open file, path starting with %userprofile%

I have a simple problem. I have a path to a file in user directory that looks like this:
%USERPROFILE%\AppData\Local\MyProg\settings.file
When I try to open it as a file
ostream = new FileStream(fileName, FileMode.Open);
It spits error because it tries to add %userprofile% to the current directory, so it becomes:
C:\Program Files\MyProg\%USERPROFILE%\AppData\Local\MyProg\settings.file
How do I make it recognise that a path starting with %USERPROFILE% is an absolute, not a relative path?
PS: I cannot use
Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)
Because I need to just open the file by its name. User specifies the name. If user specifies "settings.file", I need to open a file relative to program dir, if user specifies a path starting with %USERPROFILE% or some other thing that converts to C:\something, I need to open it as well!

Use Environment.ExpandEnvironmentVariables on the path before using it.
var pathWithEnv = #"%USERPROFILE%\AppData\Local\MyProg\settings.file";
var filePath = Environment.ExpandEnvironmentVariables(pathWithEnv);
using(ostream = new FileStream(filePath, FileMode.Open))
{
//...
}

Try using ExpandEnvironmentVariables on the path.

Use the Environment.ExpandEnvironmentVariables static method:
string fileName= Environment.ExpandEnvironmentVariables(fileName);
ostream = new FileStream(fileName, FileMode.Open);

I use this in my Utilities library.
using System;
namespace Utilities
{
public static class MyProfile
{
public static string Path(string target)
{
string basePath =
Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) +
#"\Automation\";
return basePath + target;
}
}
}
So I can simply use e.g. "string testBenchPath = MyProfile.Path("TestResults");"

You can use the Environment.Username constant as well. Both of the %USERPROFILE% and this Environment variable points the same( which is the currently logged user). But if you choose this way, you have to concatenate the path by yourself.

Creating an Epub file with a Zip library

HI All,
I am trying to zip up an Epub file i have made using c#
Things I have tried
Dot Net Zip http://dotnetzip.codeplex.com/
- DotNetZip works but epubcheck fails the resulting file (**see edit below)
ZipStorer zipstorer.codeplex.com
- creates an epub file that passes validation but the file won't open in Adobe Digital Editions
7 zip
- I have not tried this using c# but when i zip the file using there interface it tells me that the mimetype file name has a length of 9 and it should be 8
In all cases the mimetype file is the first file added to the archive and is not compressed
The Epub validator that I'am using is epubcheck http://code.google.com/p/epubcheck/
if anyone has succesfully zipped an epub file with one of these libraries please let me know how or if anyone has zipped an epub file successfully with any other open source zipping api that would also work.
EDIT
DotNetZip works, see accepted answer below.

If you need to control the order of the entries in the ZIP file, you can use DotNetZip and the ZipOutputStream.
You said you tried DotNetZip and it (the epub validator) gave you an error complaining about the mime type thing. This is probably because you used the ZipFile type within DotNetZip. If you use ZipOutputStream, you can control the ordering of the zip entries, which is apparently important for epub (I don't know the format, just surmising).
EDIT
I just checked, and the epub page on Wikipedia describes how you need to format the .epub file. It says that the mimetype file must contain specific text, must be uncompressed and unencrypted, and must appear as the first file in the ZIP archive.
Using ZipOutputStream, you would do this by setting CompressionLevel = None on that particular ZipEntry - that value is not the default.
Here's some sample code:
private void Zipup()
{
string _outputFileName = "Fargle.epub";
using (FileStream fs = File.Open(_outputFileName, FileMode.Create, FileAccess.ReadWrite ))
{
using (var output= new ZipOutputStream(fs))
{
var e = output.PutNextEntry("mimetype");
e.CompressionLevel = CompressionLevel.None;
byte[] buffer= System.Text.Encoding.ASCII.GetBytes("application/epub+zip");
output.Write(buffer,0,buffer.Length);
output.PutNextEntry("META-INF/container.xml");
WriteExistingFile(output, "META-INF/container.xml");
output.PutNextEntry("OPS/"); // another directory
output.PutNextEntry("OPS/whatever.xhtml");
WriteExistingFile(output, "OPS/whatever.xhtml");
// ...
}
}
}
private void WriteExistingFile(Stream output, string filename)
{
using (FileStream fs = File.Open(fileName, FileMode.Read))
{
int n = -1;
byte[] buffer = new byte[2048];
while ((n = fs.Read(buffer,0,buffer.Length)) > 0)
{
output.Write(buffer,0,n);
}
}
}
See the documentation for ZipOutputStream here.

Why not make life easier?
private void IonicZip()
{
string sourcePath = "C:\\pulications\\";
string fileName = "filename.epub";
// Creating ZIP file and writing mimetype
using (ZipOutputStream zs = new ZipOutputStream(sourcePath + fileName))
{
var o = zs.PutNextEntry("mimetype");
o.CompressionLevel = CompressionLevel.None;
byte[] mimetype = System.Text.Encoding.ASCII.GetBytes("application/epub+zip");
zs.Write(mimetype, 0, mimetype.Length);
}
// Adding META-INF and OEPBS folders including files
using (ZipFile zip = new ZipFile(sourcePath + fileName))
{
zip.AddDirectory(sourcePath + "META-INF", "META-INF");
zip.AddDirectory(sourcePath + "OEBPS", "OEBPS");
zip.Save();
}
}

For anyone like me who's searching for other ways to do this, I would like to add that the ZipStorer class from Jaime Olivares is a great alternative. You can copy the code right into your project, and it's very easy to choose between 'deflate' and 'store'.
https://github.com/jaime-olivares/zipstorer
Here's my code for creating an EPUB:
Dictionary<string, string> FilesToZip = new Dictionary<string, string>()
{
{ ConfigPath + #"mimetype", #"mimetype"},
{ ConfigPath + #"container.xml", #"META-INF/container.xml" },
{ OutputFolder + Name.Output_OPF_Name, #"OEBPS/" + Name.Output_OPF_Name},
{ OutputFolder + Name.Output_XHTML_Name, #"OEBPS/" + Name.Output_XHTML_Name},
{ ConfigPath + #"style.css", #"OEBPS/style.css"},
{ OutputFolder + Name.Output_NCX_Name, #"OEBPS/" + Name.Output_NCX_Name}
};
using (ZipStorer EPUB = ZipStorer.Create(OutputFolder + "book.epub", ""))
{
bool First = true;
foreach (KeyValuePair<string, string> File in FilesToZip)
{
if (First) { EPUB.AddFile(ZipStorer.Compression.Store, File.Key, File.Value, ""); First = false; }
else EPUB.AddFile(ZipStorer.Compression.Deflate, File.Key, File.Value, "");
}
}
This code creates a perfectly valid EPUB file. However, if you don't need to worry about validation, it seems most eReaders will accept an EPUB with a 'deflate' mimetype. So my previous code using .NET's ZipArchive produced EPUBs that worked in Adobe Digital Editions and a PocketBook.