1、QT 专用接口：

extern "C" bool DWAPI_SendCmd(QString cmd);

2、C/C++ 使用：

extern "C" bool DWAPI_SendCmdA(const char * cmd);

3、C# 引入 DLL：

[DllImport("dwApiLib.dll", EntryPoint = "DWAPI_SendCmdA", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]

private static extern bool DWAPI_SendCmdA(StringBuilder fullPath);