C#からC++のDLLを呼び出す際の最低限の内容(文字列のマーシャリング含む)

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

// DllImportに必要
using System.Runtime.InteropServices;

namespace threadTester
{
    /// <summary>
    /// MainWindow.xaml の相互作用ロジック
    /// </summary>
    public partial class MainWindow : Window
    {
        //※これは必須：CallingConvention = CallingConvention.Cdecl
        [DllImport("ThreadDll.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Unicode)]
        private extern static int DllEntryPint(StringBuilder test);

        public MainWindow()
        {
            InitializeComponent();
        }

        // メインフォームにButton「ExecuteButton」、Label「resultLabel」を用意しておくこと
        private void ExecuteButton_Click(object sender, RoutedEventArgs e)
        {
            StringBuilder sb = new StringBuilder(256);
            sb.Append("test");

            int retCode = DllEntryPint(sb);

            resultLabel.Content = "ResultCode : " + retCode;
        }
    }
}

ThreadDll.cpp

#pragma once

// ThreadDll.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "ThreadDll.h"

void ThreadManager::SetProperty(const wchar_t* name)
{
	printf("in SetProperty!\n");
	wcscat_s(_name, MAX_PATH, name);
}

void ThreadManager::Execute()
{
	printf("in Execute!\n");
	wprintf(L"args : %ls", _name);
}

int DllEntryPint()
{
	return 11;
}

int DllEntryPint(LPCWSTR name)
{
	printf("in DllEntryPint!\n");

	//ThreadManager* tm = new ThreadManager();
	//tm->SetProperty(name);
	//tm->Execute();

	return 11;
}

ThreadDll.h

#pragma once

#include <stdio.h>

#ifdef THREADDLL_EXPORTS
#define THREADDLL_API __declspec(dllexport) 
#else
#define THREADDLL_API __declspec(dllimport) 
#endif

#define MAX_PATH 260

// 進捗管理用構造体
typedef struct {
	wchar_t* name;
	int max;
	int current;
	int status;
	int result;
} STATUS_STRUCT;

// スレッド管理用クラス
class ThreadManager {
private:
	wchar_t _name[MAX_PATH];

public:
	STATUS_STRUCT* _status;

	void SetProperty(const wchar_t* name);
	void Execute();

};

// 外部参照関数
//extern "C" THREADDLL_API int DllEntryPint();
extern "C" THREADDLL_API int DllEntryPint(LPCWSTR name);