将非托管 dll 嵌入到托管 C# dll 中

Question

我有一个托管 C# dll，它使用 DLLImport 来使用非托管 C++ dll。 一切都运转良好。 但是，我想将该非托管 DLL 嵌入我的托管 DLL 中，如 Microsoft 所解释的：

http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.dllimportattribute.dllimportattribute.aspx

所以我将非托管 dll 文件添加到我的托管 dll 中项目，将属性设置为“嵌入式资源”并将 DLLImport 修改为

[DllImport("Unmanaged Driver.dll, Wrapper Engine, Version=1.0.0.0,
Culture=neutral, PublicKeyToken=null",
CallingConvention = CallingConvention.Winapi)]

： “Wrapper Engine”是我的托管 DLL 的程序集名称 “Unmanaged Driver.dll”是非托管 DLL

当我运行时，我得到：

访问被拒绝。 （HRESULT 异常：0x80070005 (E_ACCESSDENIED))

我从 MSDN 和 http://blogs.msdn.com/suzcook/ 看到这应该是可能的...

Answer 1

如果您在初始化期间自行将非托管 DLL 提取到临时目录，并在使用 P/Invoke 之前使用 LoadLibrary 显式加载它，则可以将非托管 DLL 嵌入为资源。 我已经使用了这个技术并且效果很好。 正如迈克尔所说，您可能更愿意将其作为单独的文件链接到程序集，但将所有内容都放在一个文件中具有其优点。 这是我使用的方法：

// Get a temporary directory in which we can store the unmanaged DLL, with
// this assembly's version number in the path in order to avoid version
// conflicts in case two applications are running at once with different versions
string dirName = Path.Combine(Path.GetTempPath(), "MyAssembly." +
  Assembly.GetExecutingAssembly().GetName().Version.ToString());
if (!Directory.Exists(dirName))
  Directory.CreateDirectory(dirName);
string dllPath = Path.Combine(dirName, "MyAssembly.Unmanaged.dll");

// Get the embedded resource stream that holds the Internal DLL in this assembly.
// The name looks funny because it must be the default namespace of this project
// (MyAssembly.) plus the name of the Properties subdirectory where the
// embedded resource resides (Properties.) plus the name of the file.
using (Stream stm = Assembly.GetExecutingAssembly().GetManifestResourceStream(
  "MyAssembly.Properties.MyAssembly.Unmanaged.dll"))
{
  // Copy the assembly to the temporary file
  try
  {
    using (Stream outFile = File.Create(dllPath))
    {
      const int sz = 4096;
      byte[] buf = new byte[sz];
      while (true)
      {
        int nRead = stm.Read(buf, 0, sz);
        if (nRead < 1)
          break;
        outFile.Write(buf, 0, nRead);
      }
    }
  }
  catch
  {
    // This may happen if another process has already created and loaded the file.
    // Since the directory includes the version number of this assembly we can
    // assume that it's the same bits, so we just ignore the excecption here and
    // load the DLL.
  }
}

// We must explicitly load the DLL here because the temporary directory 
// is not in the PATH.
// Once it is loaded, the DllImport directives that use the DLL will use
// the one that is already loaded into the process.
IntPtr h = LoadLibrary(dllPath);
Debug.Assert(h != IntPtr.Zero, "Unable to load library " + dllPath);

Answer 2

这是我的解决方案，它是 JayMcClellan 答案的修改版本。 将以下文件保存到 class.cs 文件中。

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

namespace Qromodyn
{
    /// <summary>
    /// A class used by managed classes to managed unmanaged DLLs.
    /// This will extract and load DLLs from embedded binary resources.
    /// 
    /// This can be used with pinvoke, as well as manually loading DLLs your own way. If you use pinvoke, you don't need to load the DLLs, just
    /// extract them. When the DLLs are extracted, the %PATH% environment variable is updated to point to the temporary folder.
    ///
    /// To Use
    /// <list type="">
    /// <item>Add all of the DLLs as binary file resources to the project Propeties. Double click Properties/Resources.resx,
    /// Add Resource, Add Existing File. The resource name will be similar but not exactly the same as the DLL file name.</item>
    /// <item>In a static constructor of your application, call EmbeddedDllClass.ExtractEmbeddedDlls() for each DLL that is needed</item>
    /// <example>
    ///               EmbeddedDllClass.ExtractEmbeddedDlls("libFrontPanel-pinv.dll", Properties.Resources.libFrontPanel_pinv);
    /// </example>
    /// <item>Optional: In a static constructor of your application, call EmbeddedDllClass.LoadDll() to load the DLLs you have extracted. This is not necessary for pinvoke</item>
    /// <example>
    ///               EmbeddedDllClass.LoadDll("myscrewball.dll");
    /// </example>
    /// <item>Continue using standard Pinvoke methods for the desired functions in the DLL</item>
    /// </list>
    /// </summary>
    public class EmbeddedDllClass
    {
        private static string tempFolder = "";

        /// <summary>
        /// Extract DLLs from resources to temporary folder
        /// </summary>
        /// <param name="dllName">name of DLL file to create (including dll suffix)</param>
        /// <param name="resourceBytes">The resource name (fully qualified)</param>
        public static void ExtractEmbeddedDlls(string dllName, byte[] resourceBytes)
        {
            Assembly assem = Assembly.GetExecutingAssembly();
            string[] names = assem.GetManifestResourceNames();
            AssemblyName an = assem.GetName();

            // The temporary folder holds one or more of the temporary DLLs
            // It is made "unique" to avoid different versions of the DLL or architectures.
            tempFolder = String.Format("{0}.{1}.{2}", an.Name, an.ProcessorArchitecture, an.Version);

            string dirName = Path.Combine(Path.GetTempPath(), tempFolder);
            if (!Directory.Exists(dirName))
            {
                Directory.CreateDirectory(dirName);
            }

            // Add the temporary dirName to the PATH environment variable (at the head!)
            string path = Environment.GetEnvironmentVariable("PATH");
            string[] pathPieces = path.Split(';');
            bool found = false;
            foreach (string pathPiece in pathPieces)
            {
                if (pathPiece == dirName)
                {
                    found = true;
                    break;
                }
            }
            if (!found)
            {
                Environment.SetEnvironmentVariable("PATH", dirName + ";" + path);
            }

            // See if the file exists, avoid rewriting it if not necessary
            string dllPath = Path.Combine(dirName, dllName);
            bool rewrite = true;
            if (File.Exists(dllPath)) {
                byte[] existing = File.ReadAllBytes(dllPath);
                if (resourceBytes.SequenceEqual(existing))
                {
                    rewrite = false;
                }
            }
            if (rewrite)
            {
                File.WriteAllBytes(dllPath, resourceBytes);
            }
        }

        [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Unicode)]
        static extern IntPtr LoadLibrary(string lpFileName);

        /// <summary>
        /// managed wrapper around LoadLibrary
        /// </summary>
        /// <param name="dllName"></param>
        static public void LoadDll(string dllName)
        {
            if (tempFolder == "")
            {
                throw new Exception("Please call ExtractEmbeddedDlls before LoadDll");
            }
            IntPtr h = LoadLibrary(dllName);
            if (h == IntPtr.Zero)
            {
                Exception e = new Win32Exception();
                throw new DllNotFoundException("Unable to load library: " + dllName + " from " + tempFolder, e);
            }
        }

    }
}

Answer 3

我不知道这是可能的 - 我猜测 CLR 需要在某处提取嵌入的本机 DLL（Windows 需要有一个文件供 DLL 加载它 - 它无法从原始内存加载图像），无论在哪里它正在尝试执行该过程没有权限的操作。

SysInternals 的进程监视器之类的东西可能会为您提供线索，如果问题是创建 DLL 文件失败...

更新：

---

啊...现在我已经能够阅读 Suzanne Cook 的文章（该页面之前没有出现在我面前），请注意，她并不是在谈论嵌入本机 DLL 作为托管 DLL 内的资源，而不是作为链接资源 - 本机 DLL 仍然需要是文件系统中自己的文件。

请参阅http://msdn.microsoft.com/en-us/library/xawyf94k。 aspx，其中显示：

资源文件未添加到输出文件中。 这与 /resource 选项不同，后者在输出文件中嵌入资源文件。

这似乎是将元数据添加到程序集中，导致本机 DLL 在逻辑上成为程序集的一部分（即使它实际上是一个单独的文件）。 因此，诸如将托管程序集放入 GAC 之类的操作将自动包含本机 DLL 等。

Answer 4

您可以尝试 Costura.Fody。 文档称，它能够处理非托管文件。 我只将它用于托管文件，它的作用就像一个魅力:)

Answer 5

人们还可以将 DLL 复制到任何文件夹，然后调用 SetDllDirectory 到该文件夹​​。 则无需调用 LoadLibrary。

[DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool SetDllDirectory(string lpPathName);