C++ 2013中的Dll需要向VB.net返回字符串

// C++ DLL代码
#include <string>

// 导出函数，用于将字符串返回给VB.net
extern "C" __declspec(dllexport) const char* GetString(const char* inputString)
{
    // 使用C++的字符串处理函数处理输入字符串
    std::string result = "Processed: ";
    result += inputString;

    // 将结果字符串转换为C-style字符串
    char* cResult = new char[result.length() + 1];
    strcpy_s(cResult, result.length() + 1, result.c_str());

    // 释放内存
    result.clear();

    // 返回结果字符串给VB.net
    return cResult;
}

Imports System.Runtime.InteropServices

Public Class Form1
    ' 导入C++ DLL中的函数
    <DllImport("YourCppDll.dll", CallingConvention:=CallingConvention.Cdecl)>
    Private Shared Function GetString(ByVal inputString As String) As IntPtr
    End Function

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        ' 调用C++ DLL中的函数并获取返回的字符串
        Dim inputString As String = "Hello from VB.net"
        Dim resultPtr As IntPtr = GetString(inputString)
        Dim resultString As String = Marshal.PtrToStringAnsi(resultPtr)

        ' 输出结果字符串
        MessageBox.Show(resultString)

        ' 释放内存
        Marshal.FreeCoTaskMem(resultPtr)
    End Sub
End Class