在混合 C++ DLL 和 WPF ZD7EFA19FBE24D3972FD745ADB6 项目中找不到名为 xxx 的入口点

Question

我正在尝试将 C++ DLL 与 WPF ZD7EFA19FBE7D3972FD74ZZ 代码混合。 我的 DLL 称为 Transcoder.dll 并具有简单的界面：

转码器.h

#define MATHLIBRARY_API __declspec(dllexport)

namespace MathLibrary
{
    class Functions
    {
    public:
        // Returns a + b  
        static MATHLIBRARY_API double Add(double a, double b);

        // Returns a * b  
        static MATHLIBRARY_API double Multiply(double a, double b);

        // Returns a + (a * b)  
        static MATHLIBRARY_API double AddMultiply(double a, double b);

    };
};

DLL 使用.def文件（在Linker->Input->Module Definition File中添加）：

LIBRARY
EXPORTS
MathLibraryFunctionsAdd = ?Add@Functions@MathLibrary@@SANNN@Z
MathLibraryFunctionsAddMultiply = ?AddMultiply@Functions@MathLibrary@@SANNN@Z
MathLibraryFunctionsMultiply = ?Multiply@Functions@MathLibrary@@SANNN@Z

和我的简单 C# WPF class：

class MathLibrary
{
    [DllImport("Transcoder.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "MathLibraryFunctionsAdd", ExactSpelling = true, PreserveSig = true)]
    static extern public double Add(double a, double b);

    [DllImport("Transcoder.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "MathLibraryFunctionsAddMultiply", ExactSpelling = true, PreserveSig = true)]
    static extern public double AddMultiply(double a, double b);

    [DllImport("Transcoder.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "MathLibraryFunctionsMultiply", ExactSpelling = true, PreserveSig = true)]
    static extern public double Multiply(double a, double b);
}

....

private async void Button_ClickAsync(object sender, RoutedEventArgs e) {
   var result = MathLibrary.Add(2.0, 3.0);
   Console.WriteLine(result);
}

一旦我调用MathLibrary.Add function。 我得到：

System.EntryPointNotFoundException: 'Unable to find an entry point named 'MathLibraryFunctionsAdd' in DLL 'Transcoder.dll'.'

dumpbin.exe /exports.\Transcoder.dll 的 Output：

File Type: DLL

  Section contains the following exports for Transcoder.dll

    00000000 characteristics
    FFFFFFFF time date stamp
        0.00 version
           1 ordinal base
           3 number of functions
           3 number of names

    ordinal hint RVA      name

          1    0 0001110E MathLibraryFunctionsAdd = @ILT+265(?Add@Functions@MathLibrary@@SANNN@Z)
          2    1 00011136 MathLibraryFunctionsAddMultiply = @ILT+305(?AddMultiply@Functions@MathLibrary@@SANNN@Z)
          3    2 00011208 MathLibraryFunctionsMultiply = @ILT+515(?Multiply@Functions@MathLibrary@@SANNN@Z)

Answer 1

这里没有错误。 由于将 DLL 复制到应用程序目录中的错误构建步骤，它不起作用。 The question above can serve as a template for how to map a C++ DLL to a C# WPF application.