Go与.NET互操作：在Go应用中调用.NET库的策略

// YourDotNetHostDLL.cpp
#include <windows.h>
#include <metahost.h> // CLR hosting APIs
#pragma comment(lib, "mscoree.lib") // 链接mscoree.lib

// 全局变量或结构体来保存CLR运行时信息
ICLRMetaHost* pMetaHost = NULL;
ICLRRuntimeInfo* pRuntimeInfo = NULL;
ICLRRuntimeHost* pHost = NULL;

// 初始化CLR
extern "C" __declspec(dllexport) HRESULT InitializeCLR(LPCWSTR dotNetVersion) {
    HRESULT hr;

    // 获取CLRMetaHost接口
    hr = CLRCreateInstance(CLSID_CLRMetaHost, IID_ICLRMetaHost, (LPVOID*)&pMetaHost);
    if (FAILED(hr)) return hr;

    // 获取指定版本的CLRRuntimeInfo接口
    hr = pMetaHost->GetRuntime(dotNetVersion, IID_ICLRRuntimeInfo, (LPVOID*)&pRuntimeInfo);
    if (FAILED(hr)) return hr;

    // 获取CLRRuntimeHost接口
    hr = pRuntimeInfo->GetInterface(CLSID_CLRRuntimeHost, IID_ICLRRuntimeHost, (LPVOID*)&pHost);
    if (FAILED(hr)) return hr;

    // 启动CLR
    hr = pHost->Start();
    if (FAILED(hr)) return hr;

    return S_OK; // 成功初始化
}

// 概念性调用.NET方法，实际实现会更复杂
extern "C" __declspec(dllexport) HRESULT CallDotNetMethod(LPCWSTR assemblyPath, LPCWSTR typeName, LPCWSTR methodName, LPCWSTR arg) {
    if (!pHost) return E_FAIL; // CLR未初始化

    // 实际的.NET方法调用需要通过 ICLRRuntimeHost::ExecuteInDefaultAppDomain
    // 或其他AppDomain管理接口来加载程序集，获取类型和方法，然后通过反射调用。
    // 这里仅作示意，返回成功
    // Example:
    // DWORD dwRetVal;
    // hr = pHost->ExecuteInDefaultAppDomain(
    //     assemblyPath,
    //     typeName,
    //     methodName,
    //     arg,
    //     &dwRetVal
    // );
    // return hr;
    return S_OK;
}

// 清理CLR资源
extern "C" __declspec(dllexport) HRESULT ShutdownCLR() {
    HRESULT hr = S_OK;
    if (pHost) {
        hr = pHost->Stop();
        pHost->Release();
        pHost = NULL;
    }
    if (pRuntimeInfo) {
        pRuntimeInfo->Release();
        pRuntimeInfo = NULL;
    }
    if (pMetaHost) {
        pMetaHost->Release();
        pMetaHost = NULL;
    }
    return hr;
}

package main

/*
#cgo LDFLAGS: -L. -lYourDotNetHostDLL // 假设DLL名为YourDotNetHostDLL.dll，且在当前目录
#include <windows.h> // 包含HRESULT等定义
#include <stdio.h>

// 声明C函数签名
extern HRESULT InitializeCLR(const wchar_t* dotNetVersion);
extern HRESULT CallDotNetMethod(const wchar_t* assemblyPath, const wchar_t* typeName, const wchar_t* methodName, const wchar_t* arg);
extern HRESULT ShutdownCLR();
*/
import "C"
import (
    "fmt"
    "syscall"
    "unsafe"
)

func main() {
    // 示例.NET版本，如.NET Framework 4.0
    dotNetVersion := syscall.StringToUTF16Ptr("v4.0.30319") 

    // 初始化CLR
    ret := C.InitializeCLR((*C.wchar_t)(unsafe.Pointer(dotNetVersion)))
    if ret != 0 {
        fmt.Printf("Failed to initialize CLR: 0x%x
", uint32(ret))
        return
    }
    fmt.Println("CLR initialized successfully.")

    // 示例调用.NET方法 (路径和名称需替换为实际值)
    assemblyPath := syscall.StringToUTF16Ptr("C:\Path\To\YourAssembly.dll")
    typeName := syscall.StringToUTF16Ptr("YourNamespace.YourClass")
    methodName := syscall.StringToUTF16Ptr("YourStaticMethod")
    arg := syscall.StringToUTF16Ptr("Hello from Go!")

    ret = C.CallDotNetMethod(
        (*C.wchar_t)(unsafe.Pointer(assemblyPath)),
        (*C.wchar_t)(unsafe.Pointer(typeName)),
        (*C.wchar_t)(unsafe.Pointer(methodName)),
        (*C.wchar_t)(unsafe.Pointer(arg)),
    )
    if ret != 0 {
        fmt.Printf("Failed to call .NET method: 0x%x
", uint32(ret))
        // 实际应用中需要更详细的错误处理
    } else {
        fmt.Println(".NET method called successfully.")
    }

    // 清理CLR资源
    ret = C.ShutdownCLR()
    if ret != 0 {
        fmt.Printf("Failed to shutdown CLR: 0x%x
", uint32(ret))
    } else {
        fmt.Println("CLR shutdown successfully.")
    }
}