C# get a string from C++ DLL

C++ DLL ：

TCHAR g_awcMessage[] = L"Hello中文"; 

char g_aszMessage[] = "Hello中文"; 

 

extern "C" __declspec(dllexport) TCHAR* __stdcall GetHelloL() 

{  

 return g_awcMessage;  

} 

 

extern "C" __declspec(dllexport) CHAR* __stdcall GetHello() 

{  

 return g_aszMessage; 

} 

 

extern "C" __declspec(dllexport) int __stdcall GetInt() 

{  

 return 100; 

}

C# P/Invoke：

[DllImport("gpDll.dll")] 

public static extern IntPtr GetHello(); 

 

[DllImport("gpDll.dll")] 

public static extern IntPtr GetHelloL(); 

 

[DllImport("gpDll.dll")] 

public static extern int GetInt(); 

 

 

private void button1_Click(object sender, EventArgs e) 

{ 

            // Not support in CF 

            //Marshal.PtrToStringAnsi 

            //Marshal.PtrToStringAuto 



            // Multibytes 會變成亂碼 

            string str =  Marshal.PtrToStringUni(GetHello()); 

    

            // Wide Character 顯示正常 

            string strL = Marshal.PtrToStringUni(GetHelloL()); 



           int n = GetInt(); 

}