Creating a file on network location in asp.net

Question

In my ASP.net application, I am creating a Text file and writing data to that file. I am saving that file in specified location on the server. This is an intranet application. When I run my application locally using Visual studio.net, I can create/write and save the file to that network location through the application, but when I deployed the application on the server and then I tried to create the file. It says "Access Denied".

I am not sure what extra things, I need to do so that I can Create a Text file and save it to a specified location.

In this application, I am authenticating a group of users who can use this application.

Do I need to take any extra steps to create the file on server location and then save the data to it. Below is my code:

string DirectoryPath = getDirectortyPath();
StreamWriter file = new StreamWriter(DirectoryPath);
file.WriteLine(FullLine);

public string getDirectortyPath(string Year,string  Quarter)
{
    return ConfigurationManager.AppSettings["ReportPath"] + ".txt";
}

Any help will be greatly apprecaited.

Does the user that the IIS process on your server runs as have the network folder mounted, and have write access to it? — ProgrammingLlama, Apr 27 '17 at 14:59
do a google search on the following `Server.MapPath and Path.Combine` you need to understand the filepaths in Web Apps are not the same as in how you would do it in Windows Apps — MethodMan, Apr 27 '17 at 15:00
And do not forget to put your StreamWriter object inside a using statement to avoid locking yourself out — Steve, Apr 27 '17 at 15:00

ste-fu · Answer 1 · 2017-04-27T15:12:50.133

Usually when developing IIS express runs under your local account. This means that it has access to the same network drives that you do.

When deployed applications typically run under the IIS_IUSRS group unless otherwise specified

You have a few options:

Allow this group access to your network drive
Run the application as your own user
Create a new user and run the application as this user

The first option is not ideal. It means that almost any web application running using the standard config on your network will have access to that network share.

The second option may be useful in the short term, but it means that the application has access to everything that your account does. If your account is an admin account and / or you have admin access to servers this could be very dangerous.

The third option is best overall, but takes a little more set up.

To set the Identity, you will need to create a new Application Pool in IIS and then using the Advanced Settings set the Identity option to the Custom account value and then enter the appropriate domain\username and password.

score 1 · Accepted Answer · answered Sep 05 '19 at 15:29

All you need to provide is the credentials for that network. That means you need to provide username and password of the network where you are going to store your files on it.

In your function add:

#region network connection
        string networkPath = \\192.168.10.19\e;
        string userName = @"anil";
        string password = "1234";
        NetworkCredential credentials = new NetworkCredential(userName, password);
        string myNetworkPath = string.Empty;
     using (new ConnectToSharedFolder(networkPath, credentials))
            {
              //your stuff here
              // your new path must include: networkpath+ [your folder]
           }
  #endregion

Create separate controller to make connection in network using above credentials

 public class ConnectToSharedFolder : IDisposable
    {
        readonly string _networkName;

        public ConnectToSharedFolder(string networkName, NetworkCredential credentials)
        {
            _networkName = networkName;

            var netResource = new NetResource
            {
                Scope = ResourceScope.GlobalNetwork,
                ResourceType = ResourceType.Disk,
                DisplayType = ResourceDisplaytype.Share,
                RemoteName = networkName
            };

            var userName = string.IsNullOrEmpty(credentials.Domain)
                ? credentials.UserName
                : string.Format(@"{0}\{1}", credentials.Domain, credentials.UserName);

            var result = WNetAddConnection2(
                netResource,
                credentials.Password,
                userName,
                0);

            if (result != 0)
            {
                throw new Win32Exception(result, "Error connecting to remote share");
            }
        }

        ~ConnectToSharedFolder()
        {
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            WNetCancelConnection2(_networkName, 0, true);
        }

        [DllImport("mpr.dll")]
        private static extern int WNetAddConnection2(NetResource netResource,
            string password, string username, int flags);

        [DllImport("mpr.dll")]
        private static extern int WNetCancelConnection2(string name, int flags,
            bool force);

        [StructLayout(LayoutKind.Sequential)]
        public class NetResource
        {
            public ResourceScope Scope;
            public ResourceType ResourceType;
            public ResourceDisplaytype DisplayType;
            public int Usage;
            public string LocalName;
            public string RemoteName;
            public string Comment;
            public string Provider;
        }

        public enum ResourceScope : int
        {
            Connected = 1,
            GlobalNetwork,
            Remembered,
            Recent,
            Context
        };

        public enum ResourceType : int
        {
            Any = 0,
            Disk = 1,
            Print = 2,
            Reserved = 8,
        }

        public enum ResourceDisplaytype : int
        {
            Generic = 0x0,
            Domain = 0x01,
            Server = 0x02,
            Share = 0x03,
            File = 0x04,
            Group = 0x05,
            Network = 0x06,
            Root = 0x07,
            Shareadmin = 0x08,
            Directory = 0x09,
            Tree = 0x0a,
            Ndscontainer = 0x0b
        }
    }

score 0 · Answer 3 · answered Apr 27 '17 at 15:01

Possible cause could be the application pool's identity doesnt have the write access to the network location where the file is being created / appended.

Make sure that application pool's identity is set to the account that has read/write access to that netowrk location.

Hope this makes sense.

score 0 · Answer 4 · answered Apr 27 '17 at 15:14

Other answers have already stated that this is presumably due to the IIS account not having the proper permissions. I'm pretty sure they are right.

From experience, there are other options; although these might not be applicable to your specific situation.

If this is a business environment, the web server might be in a different domain than the employee machines; and simply be unable to access the file server regardless of access rights.
The web server could be relying on different DNS entries and might not know the server by the same name that you do.*

*This is a personal anecdote. I had set up some code to write a file to \\fileserverName\directory\file.txt; but this did not work after publishing the application.
As it turns out, when I used \\fileserverName.domain.local\directory\file.txt, it did work. The web server simply did not know the shortname for the server; as it was only added onto our office domain, not the webserver domain.

Creating a file on network location in asp.net

4 Answers4

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