Question

我正在尝试将字符串从C＃传递给C DLL。从我所读到的.NET应该为我做从字符串到char *的转换，但是我得到＆＃34;错误CS1503：参数＆＃39; 1＆＃39;：不能转换为＆＃39;字符串＆＃39; to＆＃39; char *＆＃39;＆＃34;有人可以告诉我哪里出错了吗？感谢。

C＃代码

[DllImport("Source.dll", ExactSpelling = true, CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
public static unsafe extern bool StreamReceiveInitialise(char* filepath);

const string test = "test";
// This method that will be called when the thread is started
public void Stream()
{
    if (StreamReceiveInitialise(test))
    {


    }
}

C DLL

extern "C"
{
    __declspec(dllexport) bool __cdecl StreamReceiveInitialise(char* filepath);
}

Answer 1

将您的外部方法声明为：

public static extern bool StreamReceiveInitialise(string filepath);

Answer 2

这样做：

[DllImport("Source.dll", CallingConvention = CallingConvention.Cdecl, CharSet=CharSet.ANSI)]
static extern bool StreamReceiveInitialise([MarshalAs(UnmanagedType.LPStr)] string filepath);

（编组为UnmanagedType.LPStr是默认值，但我喜欢显式）。

Answer 3

使用StringBuilder代替char *。见this

[DllImport("Source.dll")]
public static extern bool StreamReceiveInitialise(StringBuilder filepath);

将字符串从C＃传递给C DLL

3 个答案: