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);

 }