如何将unicode字符串从c＃传输到c / c ++ dll

Question

我从C＃调用C / C ++ DLL函数，并且该函数具有wchar_t* parameter时出现问题。我将参数从wchar_t*修改为char*，然后一切正常。为什么？如何使其与wchar_t*一起正常工作？

这是我的代码：

C＃

[DllImport("kernel32")]
private static extern IntPtr LoadLibraryEx(string fileName, IntPtr hFile, uint loadFlag);

[DllImport("kernel32.dll")]
public static extern IntPtr GetProcAddress(IntPtr lib, string funcName);

[DllImport("kernel32.dll")]
public static extern bool FreeLibrary(IntPtr lib);

delegate void DllTestFunc(string str, byte[] data, int length);

static void Main(string[] args)
{   
    var dllInstance = LoadLibraryEx(@"D:\Development\NativeDll\x64\Debug\NativeDll.dll", IntPtr.Zero, 0x0008);
    var ptr = GetProcAddress(dllInstance, "DllTestFunc");
    var func = Marshal.GetDelegateForFunctionPointer<DllTestFunc>(ptr);
    var inputStr = @"E:\test.dat";
    var data = new byte[100];
    data[0] = 0x55;
    func(inputStr, data, 2020);
    FreeLibrary(dllInstance);
}

C / C ++代码：

void __stdcall DllTestFunc(wchar_t* str1, unsigned char* data, const int length)

{

    cout << str1 << endl;

    cout << int(data[0]) << endl;

    cout << length << endl;**strong text**

}

因为我需要使用wchar_t*，如何解决？

Answer 1

您可能需要告诉编组员如何传递您的代表的str参数：

delegate void DllTestFunc([MarshalAs(UnmanagedType.LPWStr)] string str, byte[] data, int length);