通过p/invoke从C#使用XGBoost DLL

/*! * \brief get number of columns * \param handle the handle to the DMatrix * \param out The output of number of columns * \return 0 when success, -1 when failure happens */XGB_DLL int XGDMatrixNumCol(DMatrixHandle handle, bst_ulong *out); 此处是我的项目的仓库.我正在使用Visual Studio Enterprise 2015.它在Windows 10 Pro(64位)上以调试"模式(针对x64)构建.可以在此处.尽管链接的存储库确实包含libxgboost.dll的副本.Here is the repo for my project. I'm using Visual Studio Enterprise 2015 . It's built in "Debug" mode (targeting x64) on Windows 10 Pro (64-bit). x64 binaries for libxgboost.dll can be found here. Although the linked repo does contain a copy of libxgboost.dll.推荐答案尝试使用似乎由DLL使用的调用约定Cdecl.Try to use the calling convention Cdecl which seems to be used by the DLL.此外，XGDMatrixCreateFromFile函数的签名是错误的.预期的参数不是指向您分配的某些内存的指针，但是该函数将自行分配内存，然后将指针作为输出参数返回.Also, the signature of the XGDMatrixCreateFromFile function is wrong. The parameter expected is not a pointer to some memory allocated by you, but the function will allocate memory itself and then return the pointer as an output parameter.尝试以下代码.请注意在XGDMatrixCreateFromFile函数的outputPtr参数上使用out关键字.Try the following code. Note the use of the the out keyword on the outputPtr parameter in the XGDMatrixCreateFromFile function.[DllImport("C:\\dev\\libs\\xgboost\\build\\Release\\libxgboost.dll", CallingConvention = CallingConvention.Cdecl)]public static extern int XGDMatrixCreateFromFile([MarshalAs(UnmanagedType.LPStr)] string file, int silent, out IntPtr outputPtr);[DllImport("C:\\dev\\libs\\xgboost\\build\\Release\\libxgboost.dll", CallingConvention = CallingConvention.Cdecl)]public static extern int XGDMatrixNumCol(IntPtr dmatrixPtr, IntPtr dmatrixColumnsPtr);static void Main(string[] args){ IntPtr dmatrixPtr; IntPtr dmatrixColumnsPtr = Marshal.AllocHGlobal(10); int result = XGDMatrixCreateFromFile("C:\\dev\\libs\\xgboost\\demo\\data\\agaricus.txt.test", 0, out dmatrixPtr); int cols = XGDMatrixNumCol(dmatrixPtr, dmatrixColumnsPtr); Marshal.FreeHGlobal(dmatrixColumnsPtr);}此方法有效时，您还可以使用ulong数据类型简化调用以获取列数:When this works, you can then also simplify the call to get the number of columns by using the ulong datatype:[DllImport("C:\\dev\\libs\\xgboost\\build\\Release\\libxgboost.dll", CallingConvention = CallingConvention.Cdecl)]public static extern int XGDMatrixCreateFromFile([MarshalAs(UnmanagedType.LPStr)] string file, int silent, out IntPtr outputPtr);[DllImport("C:\\dev\\libs\\xgboost\\build\\Release\\libxgboost.dll", CallingConvention = CallingConvention.Cdecl)]public static extern int XGDMatrixNumCol(IntPtr dmatrixPtr, out ulong dmatrixColumnsPtr);static void Main(string[] args){ IntPtr dmatrixPtr; ulong dmatrixColumns; int result = XGDMatrixCreateFromFile("C:\\dev\\libs\\xgboost\\demo\\data\\agaricus.txt.test", 0, out dmatrixPtr); int cols = XGDMatrixNumCol(dmatrixPtr, out dmatrixColumns);} 这篇关于通过p/invoke从C#使用XGBoost DLL的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！