Visual Studio 2015 即使在 bin 文件夹中复制后也找不到外部 .dll，但只有在复制到 c：\Windows\ 后才找到

问：

我尝试在Visual Studio 2015中构建一个Web项目，该项目引用了c# .dll项目“dotnetWrapper”，它是c++项目“managedDllWrapper”的c#包装器，其中包括一些第三方64位本机c++ .dll。

引用的项目和 Web 项目在 .Net Framework 4.6.1 和 x64 上运行。VS2015 使用 iis express 64 位。

一切都很好。

当我在VS2015中启动本地Web服务器（点击绿色的开始按钮）时，我收到错误消息，指出找不到“managedDllWrapper.dll”或其依赖项之一：

“/”应用程序中的服务器错误。

无法加载文件或程序集“managedDllWrapper.DLL”或其依赖项之一。无法找到指定的模块

说明：执行当前 Web 请求期间发生未经处理的异常。请查看堆栈跟踪，了解有关错误及其在代码中的来源的详细信息。

异常详细信息：System.IO.FileNotFoundException：无法加载文件或程序集“managedDllWrapper.DLL”或其依赖项之一。无法找到指定的模块

源错误：

在执行当前 Web 请求期间生成了未经处理的异常。可以使用下面的异常堆栈跟踪来识别有关异常来源和位置的信息。

堆栈跟踪：

[FileNotFoundException：无法加载文件或程序集“managedDllWrapper.DLL”或其依赖项之一。无法找到指定的模块 System.Reflection.RuntimeAssembly._nLoad （AssemblyName 文件名、 字符串 codeBase、 证据 assemblySecurity、 RuntimeAssembly locationHint、 StackCrawlMark& stackMark、 IntPtr pPrivHostBinder、 Boolean throwOnFileNotFound、 Boolean forIntrospection、 Boolean suppressSecurityChecks） +0

System.Reflection.RuntimeAssembly.InternalLoadAssemblyName （AssemblyName assemblyRef， Evidence assemblySecurity， RuntimeAssembly reqAssembly， StackCrawlMark& stackMark， IntPtr pPrivHostBinder， Boolean throwOnFileNotFound， Boolean forIntrospection， Boolean suppressSecurityChecks） +234

System.Reflection.RuntimeAssembly.InternalLoad （字符串 assemblyString、 证据 assemblySecurity、 StackCrawlMark& stackMark、 IntPtr pPrivHostBinder、 布尔值 forIntrospection） +108

System.Reflection.RuntimeAssembly.InternalLoad（字符串 assemblyString、 证据 assemblySecurity、 StackCrawlMark& stackMark、 布尔值 forIntrospection） +25

System.Reflection.Assembly.Load（字符串程序集字符串）+34 System.Web.Configuration.CompilationSection.LoadAssemblyHelper （字符串 assemblyName， 布尔值 starDirective） +49

[配置错误异常：无法加载文件或程序集“managedDllWrapper.DLL”或其依赖项之一。无法找到指定的模块

System.Web.Configuration.CompilationSection.LoadAssemblyHelper （字符串 assemblyName， 布尔值 starDirective） +772

System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory（） +259

System.Web.Configuration.CompilationSection.LoadAssembly（程序集信息ai） +163

System.Web.Compilation.<>c.b__143_0（AssemblyInfo ai） +29

System.Linq.d__16'2.移动下一个（） +293

System.Linq.d__66'1.移动下一个（） +100

System.Linq.d__63'1.移动下一个（） +73

System.Web.UI.Util.GetTypeFromAssemblies （IEnumerable 程序集，字符串类型名称，布尔值 ignoreCase） +217

System.Web.Compilation.BuildManager.GetType（字符串类型名称，布尔 throwOnError，布尔值 ignoreCase）+266

System.Web.Configuration.HandlerFactoryCache.GetTypeWithAssert（字符串类型） +48

System.Web.Configuration.HandlerFactoryCache.GetHandlerType（字符串类型） +17

System.Web.Configuration.HandlerFactoryCache.ctor（字符串类型） +25

System.Web.HttpApplication.GetFactory（字符串类型） +104

System.Web.MaterializeHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（） +262

System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +137

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.6.1055.0

Note that the native dlls (the dependencies) are in the web-project bin folder (copied manually).

When I copy the native dlls into my C:\Windows\ folder, the web application works smoothly and fine. Somehow, the web-application's dll search path points only to the C:\Windows\ folder, but it should also look into the webapp execution (bin) folder, right?

When I don't do a web-application, but a C# console test-application, which also includes the wrapper with all dlls, the copying of the dlls into the test-app bin folder works fine and the application runs. Only the web-application has this problem, not to accept the dlls in its bin folder.

Also, when I copy the dlls into the C:\Windows\ directory, and run the web-application, and then try to delete the dlls again, it says they cannot be deleted because

because the file is open in IIS Express Worker Process.

So, maybe it is a problem of the IIS and not of VS2015, but I cannot configure my IIS (or I don't know how). I use the IIS express which comes with Visual Studio 2015.

All my research in Google and stackoverflow resulted in:

• copy dlls to bin folder (tried, but does not work as described above, only works for a C# console app, but not for a web-app).
• reference dlls directly in the project (not possible:)

  "[..].dll could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component."

• check if everything is 64-bit, and same .Net version (checked, 64 bit, .Net 4.6.1. Also: it works fine for a console app, but not web-app).
• change the web.config to add further .dll folders. But this did not help either.

I would be happy if the .dll could be found by my web-project in a different folder than C:\Windows\ , since I doubt I will be allowed to add 17 .dll to the C:\Windows\ folder on MS azurewebsites when I want to publish the site. Then, the path should be somehow within the application folders.