用 LoadLibraryExW 函数测试加载 dll （CSharp、Windows）

效果如下：

$ llbtest "E:\Developer\emgucv-windesktop 3.3.0.2824\libs\x64"
LoadLibraryExW PATH: E:\Developer\emgucv-windesktop 3.3.0.2824\libs\x64
E:\Developer\emgucv-windesktop 3.3.0.2824\libs\x64\concrt140.dll......[OK] ......Free: [OK]
E:\Developer\emgucv-windesktop 3.3.0.2824\libs\x64\cvextern.dll......[OK] ......Free: [OK]
E:\Developer\emgucv-windesktop 3.3.0.2824\libs\x64\msvcp140.dll......[OK] ......Free: [OK]
E:\Developer\emgucv-windesktop 3.3.0.2824\libs\x64\opencv_ffmpeg330_64.dll......[OK] ......Free: [OK]
E:\Developer\emgucv-windesktop 3.3.0.2824\libs\x64\vcruntime140.dll......[OK] ......Free: [OK]
-- Completed --

llbtest.cs 源代码：

用csc llbtest.cs编译即可

 using System;
 using System.ComponentModel;
 using System.IO;
 using System.Runtime.InteropServices;

 class Program
 {
     static void Main(string[] args)
     {
         if (args.Length ==  || args.Length > )
         {
             ShowHelp();
             return;
         }
         var path = args[];
         if (!Directory.Exists(path))
         {
             ShowHelp();
             return;
         }

         var files = Directory.EnumerateFiles(path, "*.dll");
         Console.WriteLine($"LoadLibraryExW PATH: {path}");
         foreach (var file in files)
         {
             Console.Write(file);
             const int loadLibrarySearchDllLoadDir = 0x00000100;
             const int loadLibrarySearchDefaultDirs = 0x00001000;
             //const int loadLibrarySearchUserDirs = 0x00000400;
             IntPtr handler = NativeMethods.LoadLibraryExW(file, IntPtr.Zero, loadLibrarySearchDllLoadDir | loadLibrarySearchDefaultDirs);
             //IntPtr handler = LoadLibraryEx(dllname, IntPtr.Zero, loadLibrarySearchUserDirs);
             if (handler == IntPtr.Zero)
             {
                 var error = Marshal.GetLastWin32Error();
                 var ex = new Win32Exception(error);
                 Console.WriteLine($"......[ERROR] {ex.NativeErrorCode}: {ex.Message}");
             }
             else
             {
                 Console.Write($"......[OK] {handler}");
                 var freeLibrary = NativeMethods.FreeLibrary(handler);
                 Console.WriteLine($"......Free: {(freeLibrary ? "[OK]" : "[ERROR]")}");
             }
         }
         Console.WriteLine("-- Completed --");
         if(args.Length ==  && args[] == "...")
         {
             Console.Write("Press any key to exit...");
             Console.ReadKey(true);
             Console.WriteLine();
         }
     }

     private static void ShowHelp()
     {
         var x = AppDomain.CurrentDomain.FriendlyName;
         Console.WriteLine($"Usage:\n\t{x} <path> [...]\n\tpath\tThe directory path that includes *.dll files\n\t...\tPause me when completed.");
     }
 }

 [StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
 public struct HINSTANCE__
 {

     /// int
     public int unused;
 }

 public partial class NativeMethods
 {

     /// Return Type: HMODULE->HINSTANCE->HINSTANCE__*
     ///lpLibFileName: LPCWSTR->WCHAR*
     ///hFile: HANDLE->void*
     ///dwFlags: DWORD->unsigned int
     [DllImport("kernel32.dll", EntryPoint = "LoadLibraryExW", SetLastError = true)]
     public static extern System.IntPtr LoadLibraryExW([In()] [MarshalAs(System.Runtime.InteropServices.UnmanagedType.LPWStr)] string lpLibFileName, System.IntPtr hFile, uint dwFlags);

     /// Return Type: BOOL->int
     ///hLibModule: HMODULE->HINSTANCE->HINSTANCE__*
     [DllImport("kernel32.dll", EntryPoint = "FreeLibrary")]
     [return: MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
     public static extern bool FreeLibrary([In()] System.IntPtr hLibModule);
 }