folderbrowserdialog on C# winforms

Question

I am using folderBrowserDialog in my winform.

I need the default or initial path to be a network location.

for eg:

folderBrowserDialog1.SelectedPath = @"\\server1\foo\bar\";

This does not work. My system is on the right network and I am able to access the directory thru my browser and run command.

Is this a non-feature? or is there a work-around? I would appreciate it if someone can guide me thru!

Thanks, Ivar

Answer 1

Windows makes a temporary mapping when you access a network resource using the \\name convention. I am not sure if there's a provision to do the same from a .net app in a concise manner. You may want to map the drive first to a letter then access it using @"Z:\foo\bar\" but obviously mapping a drive may not be something you want to do if your app is deployed in a way that prevents it.

Answer 2

In my experience, .NET has always been hit-or-miss with UNC paths. Sometimes it works and sometimes it doesn't. I'm sure there's a good explanation for it, but early on, I searched and searched without finding an answer.

Rather than deal with the issue, I just adopted the policy that it's better to map a drive myself and then disconnect when done in code. (If you find the answer, I'd be interested in knowing why this is, but since I have a working solution, I don't care enough to research it myself.) It works for us 100% of the time, and it's very easy. I created a class for doing it, since it's such a common task in our shop.

I don't know if you're open to the idea, at any rate, but if you're interested, and don't already have the code, our routine is pasted in below. It would be fairly simple to check for an open drive letter, and just map it, then disconnect when done.

public static class NetworkDrives
    {
        public static bool  MapDrive(string DriveLetter, string Path, string Username, string Password)
        {

            bool ReturnValue = false;

            if(System.IO.Directory.Exists(DriveLetter + ":\\"))
            {
                DisconnectDrive(DriveLetter);
            }
            System.Diagnostics.Process p = new System.Diagnostics.Process();
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.CreateNoWindow = true;
            p.StartInfo.RedirectStandardError = true;
            p.StartInfo.RedirectStandardOutput = true;

            p.StartInfo.FileName = "net.exe";
            p.StartInfo.Arguments = " use " + DriveLetter + ": " + Path + " " + Password + " /user:" + Username;
            p.Start();
            p.WaitForExit();

            string ErrorMessage = p.StandardError.ReadToEnd();
            string OuputMessage = p.StandardOutput.ReadToEnd();
            if (ErrorMessage.Length > 0)
            {
                throw new Exception("Error:" + ErrorMessage);
            }
            else
            {
                ReturnValue = true;
            }
            return ReturnValue;
        }
        public static bool DisconnectDrive(string DriveLetter)
        {
            bool ReturnValue = false;
            System.Diagnostics.Process p = new System.Diagnostics.Process();
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.CreateNoWindow = true;
            p.StartInfo.RedirectStandardError = true;
            p.StartInfo.RedirectStandardOutput = true;

            p.StartInfo.FileName = "net.exe";
            p.StartInfo.Arguments = " use " + DriveLetter + ": /DELETE";
            p.Start();
            p.WaitForExit();

            string ErrorMessage = p.StandardError.ReadToEnd();
            string OuputMessage = p.StandardOutput.ReadToEnd();
            if (ErrorMessage.Length > 0)
            {
                throw new Exception("Error:" + ErrorMessage);
            }
            else
            {
                ReturnValue = true;
            }
            return ReturnValue;
        }

    }