load_library_ex_experiment.cs

// Answer is a slight diff of Ed Bayiate's answer on Stack Overflow
// Answer URI: http://stackoverflow.com/a/6903367/3543437
// Question URI: http://stackoverflow.com/questions/6903256/how-to-programmatically-check-c-dll-files-and-c-sharp-dll-files-for-references
// Answer Author Profile URI: http://stackoverflow.com/users/695833/ed-bayiates

using System;
using System.IO;
using System.Diagnostics;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices; 

namespace CA
{
    class Program
    {
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        public static extern IntPtr GetModuleHandle(string lpModuleName);

        [DllImport("kernel32.dll")]
        static extern IntPtr LoadLibrary(string dllToLoad);

        [DllImport("kernel32.dll")]
        static extern IntPtr LoadLibraryEx(string lpFileName, IntPtr hFile, uint dwFlags);
        const UInt32 DONT_RESOLVE_DLL_REFERENCES = 0x00000001;
        const UInt32 LOAD_WITH_ALTERED_SEARCH_PATH = 0x00000008;

        [DllImport("kernel32.dll")]
        static extern bool FreeLibrary(IntPtr hModule);

        [DllImport("kernel32.dll")]
        static extern UInt32 GetLastError();

        static void CheckUnmanagedDll(string DllName)
        {
            IntPtr hModule = LoadLibraryEx(DllName, new IntPtr(), LOAD_WITH_ALTERED_SEARCH_PATH);
            if (hModule.Equals(IntPtr.Zero))
            {
                Console.WriteLine("Can't find " + DllName);
            }
            FreeLibrary(hModule);
        }


        static int Main(string [] args)
        {
            CheckUnmanagedDll("C:\\pathToFile\\file.ext");
            return 0;
        }
    }
}

This is not working in my sample application, it doesn't have any related line of code.