How to convert local path to UNC (Universal) File Path in C#

In your controller initialize class obj:

LocalPathToUNCPathConversion obj = new LocalPathToUNCPathConversion();
string localPath = "filename"; //give locally mapped network drive file path
string UNCFilePath = obj.GetUniversalName(localPath);

write logic in a separate class file named as LocalPathToUNCPathConversion.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.IO;
using System.Runtime.InteropServices;
using System.ComponentModel;

namespace YourProjectName
{
public class LocalPathToUNCPathConversion
{
[DllImport("mpr.dll", CharSet = CharSet.Unicode)]
[return: MarshalAs(UnmanagedType.U4)]
static extern int WNetGetUniversalName(
string lpLocalPath,
[MarshalAs(UnmanagedType.U4)] int dwInfoLevel,
IntPtr lpBuffer,
[MarshalAs(UnmanagedType.U4)] ref int lpBufferSize);

const int UNIVERSAL_NAME_INFO_LEVEL = 0x00000001;
const int REMOTE_NAME_INFO_LEVEL = 0x00000002;

const int ERROR_MORE_DATA = 234;
const int NOERROR = 0;

public string GetUniversalName(string localPath)
{
// The return value.
string retVal = null;

// The pointer in memory to the structure.
IntPtr buffer = IntPtr.Zero;

// Wrap in a try/catch block for cleanup.
try
{
// First, call WNetGetUniversalName to get the size.
int size = 0;

// Make the call.
// Pass IntPtr.Size because the API doesn't like null, even though
// size is zero. We know that IntPtr.Size will be
// aligned correctly.
int apiRetVal = WNetGetUniversalName(localPath, UNIVERSAL_NAME_INFO_LEVEL, (IntPtr)IntPtr.Size, ref size);

// If the return value is not ERROR_MORE_DATA, then
// raise an exception.
if (apiRetVal != ERROR_MORE_DATA)
// Throw an exception.
throw new Win32Exception(apiRetVal);

// Allocate the memory.
buffer = Marshal.AllocCoTaskMem(size);

// Now make the call.
apiRetVal = WNetGetUniversalName(localPath, UNIVERSAL_NAME_INFO_LEVEL, buffer, ref size);

// If it didn't succeed, then throw.
if (apiRetVal != NOERROR)
// Throw an exception.
throw new Win32Exception(apiRetVal);

// Now get the string. It's all in the same buffer, but
// the pointer is first, so offset the pointer by IntPtr.Size
// and pass to PtrToStringAnsi.
retVal = Marshal.PtrToStringAuto(new IntPtr(buffer.ToInt64() + IntPtr.Size), size);
retVal = retVal.Substring(0, retVal.IndexOf('\0'));
}
finally
{
// Release the buffer.
Marshal.FreeCoTaskMem(buffer);
}

// First, allocate the memory for the structure.

// That's all folks.
return retVal;
}
}
}

Convert local path to UNC (Universal) File Path using Java Script ActiveXObject