从C ++ / CLI加载相互依赖的程序集 [英] Loading interdependent assemblies from C++/CLI

问题描述

我想从C ++ / CLI加载两个程序集;程序集A依赖程序集B，都是VB.Net项目（3.5）。我希望他们从一个字节数组加载，所以我使用Assembly :: Load（），但是当我试图从程序集A实例化一个类，框架忽略以前加载的程序集B，并尝试重新加载它，失败，因为它不在搜索路径中。程序集的名称是相同的，所以我不知道为什么它失败。为了测试的目的，我的程序直接从编译的映像加载字节，但实际代码将加载不同。这是我的测试代码：

  #includestdafx.h
 
 using namespace System; 
 using namespace System :: Windows :: Forms; 
 using namespace System :: IO; 
 using namespace System :: Reflection; 
 
 [STAThreadAttribute] 
 int main（array< System :: String ^> ^ args）
 {
 array< unsigned char& 
 FileStream ^ f; 
 
 f = gcnew FileStream（Lc：\\ ... \\AssemblyB.dll，FileMode :: Open）; 
 bytes = gcnew array< unsigned char>（（int）f-> Length）; 
 f-> Read（bytes，0，（int）f-> Length）; 
 f-> Close（）; 
 f = nullptr; 
 Assembly ^ assemblyb = Assembly :: Load（bytes）; 
 
 f = gcnew FileStream（Lc：\\ ... \\AssemblyA.dll，FileMode :: Open）; 
 bytes = gcnew array< unsigned char>（（int）f-> Length）; 
 f-> Read（bytes，0，（int）f-> Length）; 
 f-> Close（）; 
 f = nullptr; 
 Assembly ^ assemblya = Assembly :: Load（bytes）; 
 
 bytes = nullptr; 
 
 //这里我得到文件未找到异常！ 
 Object ^ mf = assemblya-> CreateInstance（LAssemblyA.MainForm）; 
 
 //除非我将assemblyb.dll复制到应用程序的文件夹中，否则没有到达这一行：
 mf-> GetType（） - > InvokeMember（LShowDialog，BindingFlags ::默认| BindingFlags :: InvokeMethod，
 mf-> GetType（） - > DefaultBinder，mf，nullptr）; 
 
 return 0; 
} 
  

错误是：

无法加载文件或程序集 AssemblyB，Version = 1.0.3650.39903，Culture = neutral，PublicKeyToken = null 或其中一个依赖项。系统找不到指定的文件。

当我检查assemblyb-> FullName时，它会正确地显示 AssemblyB，Version = 1.0.3650.39903，文件=中立，PublicKeyToken = null '。

当然，如果我将AssemblyB.dll复制到我的测试程序的文件夹，代码工作正常，

（顺便说一下，我的第二个步骤将尝试让AssemblyA使用我的C ++ / CLI exe将公开的类。）

解决方案

好吧，我只是尴尬自己。

  //这个类只是用于为assemblyB持有一个管理的静态变量
 ref class解析器{
 public：
 static Assembly ^ assemblyB; 
}; 
 
 //这是解析程序集的委托
 Assembly ^ ResolveHandler（Object ^ Sender，ResolveEventArgs ^ args）
 {
 //警告： args为程序集名称！ 
 return Resolver :: assemblyB; 
} 
。 
。 
。 
 [STAThreadAttribute] 
 int main（array< System :: String ^> ^ args）
 {
 //设置AssemblyResolve事件的处理程序
 AppDomain :: CurrentDomain-> AssemblyResolve + = gcnew ResolveEventHandler（ResolveHandler）; 
。 
。 
。 
 //将assemblyb加载到可用于解析器委托的静态变量
 Resolver :: assemblyb = Assembly :: Load（bytes）; 
。 
。 
。 
  

我希望有人发现这很有用。 ：）

I want to load two assemblies from C++/CLI; assembly A depends on assembly B, and both are VB.Net projects (3.5). I want them to load from a byte array, so I use Assembly::Load(), but when I try to instantiate a class from assembly A, the framework ignores the previously loaded assembly B and attempts to load it again, which fails because it is not in the search path. The "Name" of the assembly is the same, so I don't know why it fails. For testing purposes, my program loads the bytes directly from the compiled image, but the real code will be loaded differently. This is my test code:

#include "stdafx.h"

using namespace System;
using namespace System::Windows::Forms;
using namespace System::IO;
using namespace System::Reflection;

[STAThreadAttribute]
int main(array<System::String ^> ^args)
{
    array<unsigned char>^ bytes;
    FileStream^     f;

    f = gcnew FileStream(L"c:\\...\\AssemblyB.dll", FileMode::Open);
    bytes = gcnew array<unsigned char>((int)f->Length);
    f->Read( bytes, 0, (int) f->Length );
    f->Close();
    f = nullptr;
    Assembly^   assemblyb = Assembly::Load(bytes);

    f = gcnew FileStream(L"c:\\...\\AssemblyA.dll", FileMode::Open);
    bytes = gcnew array<unsigned char>((int)f->Length);
    f->Read( bytes, 0, (int) f->Length );
    f->Close();
    f = nullptr;
    Assembly^   assemblya = Assembly::Load(bytes);

    bytes = nullptr;

    // Here I get the file not found exception!
    Object^     mf = assemblya->CreateInstance(L"AssemblyA.MainForm");

    // This line is not reached unless I copy assemblyb.dll to my app's folder:
    mf->GetType()->InvokeMember(L"ShowDialog",BindingFlags::Default | BindingFlags::InvokeMethod,
                                mf->GetType()->DefaultBinder, mf, nullptr );

    return 0;
}

The error is:

Could not load file or assembly 'AssemblyB, Version=1.0.3650.39903, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.

When I check assemblyb->FullName, it says exactly 'AssemblyB, Version=1.0.3650.39903, Culture=neutral, PublicKeyToken=null'.

Of course, if I copy AssemblyB.dll to my test program's folder the code works just fine, but that's not what I want.

Any ideas?

(By the way, my second step will be attempt to make AssemblyA use classes that my C++/CLI exe will expose.)

解决方案

OK, I just embarrased myself. It's all in the docs.

// This class is just for holding a managed static variable for assemblyB
ref class Resolver {
public:
    static  Assembly^	assemblyB;
};

// This is the delegate for resolving assemblies
Assembly^ ResolveHandler(Object^ Sender, ResolveEventArgs^ args)
{
    // Warning: this should check the args for the assembly name!
    return Resolver::assemblyB;
}
.
.
.
[STAThreadAttribute]
int main(array<System::String ^> ^args)
{
    // Set up the handler for the AssemblyResolve event
    AppDomain::CurrentDomain->AssemblyResolve += gcnew ResolveEventHandler( ResolveHandler );
.
.
.
    // Load assemblyb into the static variable available to the resolver delegate
    Resolver::assemblyb = Assembly::Load(bytes);
.
.
.

I hope someone finds this useful. :)

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