Reading files in a folder one by one in C#

Question

I have a simple question, but that it's driving me crazy. I have a folder with a lot of JSON files inside, I need just to open those files one by one and do things. So, I need to open the first one, read it and do something then go to the second one etc. until the last.

Here the code I tried, searching on web:

string folderpath = @"C:\Users\rfo\Desktop\MM\VM DB\nv - master\nvd";
            var fixedfolderpath = Environment.ExpandEnvironmentVariables(folderpath);
            string [] filesnumber = Directory.GetFiles(fixedfolderpath, "*.json");
            foreach (string filename in filesnumber)
            {
                var jsonFull = System.IO.File.ReadAllText(filename);

But I keep gettin error DirectoryNotFoundException: Could not find a part of the path on the browser. I'm using asp.net CORE 3 and visual studio 2019.

The AppPool probably has no access to the users folder. And use Server.MapPath. — VDWWD, Dec 04 '19 at 11:20
could be an access rights issue. move the folder to shared drive have to access to asp.net user — Krishna Varma, Dec 04 '19 at 11:31
please print output of fixedfolderpath, and do an if Directory.Exist(fixedfolderpath) before Directory.GetFiles — Stefano Balzarotti, Dec 04 '19 at 11:33
@JeroenvanLangen fixedfolderpath contains a lot of JSON files. — Rob None, Dec 04 '19 at 11:44
@KrishnaMohanVarma For example in a folder under the solution pattern? — Rob None, Dec 04 '19 at 11:45
@RobNone preferably the folder should be outside solution path — Krishna Varma, Dec 04 '19 at 11:55
In IIS you're supposed to access folders under the application root folder; so, create a folder under your IIS site and put your files in there, as you're not supposed to access the desktop folder anyways — Rubens Farias, Dec 04 '19 at 12:24

score 0 · Answer 1 · answered Dec 04 '19 at 11:21

0

If you want to get the files from your desktop, you could use this instead:

string path = Path.Combine(
    Environment.GetFolderPath(Environment.SpecialFolder.Desktop), 
    @"MM\VM DB\nv - master\nvd");

But you probably got access right problems

answered Dec 04 '19 at 11:21

Jeroen van Langen

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_"If you want to get the files from your desktop"_ - no, you don't want that in an ASP.NET application which will presumably run in IIS. Your Application Pool user doesn't have a desktop folder loaded by default. – CodeCaster Dec 04 '19 at 11:29
Not working, I guess i still have rights problems. If I would move it under a solution folder? – Rob None Dec 04 '19 at 11:47
That would be better – Jeroen van Langen Dec 04 '19 at 12:55

score 0 · Answer 2 · answered Dec 05 '19 at 03:21

As others suggest, it's better to move the files inside the solution. For example, you could copy those files into the project folder:

├───YourApp.csproj                      # your `*.csproj`
├───Controllers/
├───Models/
├───Views/
├───wwwroot/
├───MM/                                 # your target folder 
│   └───VM/
│       └───VM DB/
│           └───nv - master/
│               └───nvd/
|                   └─── *.json

Apart from that, don't forget to add a configuration in your *.csproj file such that your json files will be copied automatically when you build/publish the app:
```
  <ItemGroup>
    <None Update="MM\**\*.*">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
  </ItemGroup>
```

Also, it seems that you're using the ASP.NET Core instead of ASP.NET. If that's the case, you could reference this folder by injecting an IWebHostEnvironment so that you invoke webHostEnv.ContentRootPath to get root directory (i.e., the project file direction in source code, and the directory of YourAssembly.dll when published).

For example, you could inject an IWebHostEnviroment instance in the controller:

public class HomeController : Controller
{
    private readonly IWebHostEnvironment _env;
    public HomeController(IWebHostEnvironment env)
    {
        this._env = env;
    }
    public IActionResult Privacy()
    {
        var dir = Path.Combine( this._env.ContentRootPath, @"MM\VM\VM DB\nv - master\nvd");
        string[] filesnumber = Directory.GetFiles(dir, "*.json");
        foreach (string filename in filesnumber)
        {
            var jsonFull = System.IO.File.ReadAllText(filename);
            ...
        }
        return Ok("hello,world");
     }
}

Finally, in case you don't like dependency injection, or cannot use dependency injection, you could use a path relative to current assembly as below:
```
 var assemDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
 var dir = Path.Combine(assemDir, @"MM\VM\VM DB\nv - master\nvd");
 string[] filesnumber = Directory.GetFiles(dir, "*.json");
```
Be careful this is not the safest way. It is suggested that we should use the DI approach (IWebHostEnviroment) if possible.

Reading files in a folder one by one in C#

2 Answers2