Question

我正在使用第三方API，并尝试将以下C＃代码转换为F＃：

[DllImport("libfsdk.so", EntryPoint = "FSDK_FeedFrame", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.Cdecl)]
private static extern int FSDK_FeedFrame_Old(int Tracker, long CameraIdx, int Image, ref long FaceCount, [Out, MarshalAs(UnmanagedType.LPArray)] long[] IDs, long MaxSizeInBytes);
public static int FeedFrame(int Tracker, long CameraIdx, int Image, ref long FaceCount, out long[] IDs, long MaxSizeInBytes)
{
    IDs = new long[MaxSizeInBytes/8];
    return FSDK_FeedFrame_Old(Tracker, CameraIdx, Image, ref FaceCount, IDs, MaxSizeInBytes);
}

到目前为止，我的尝试是：

[<DllImport("libfsdk.so", EntryPoint = "FSDK_FeedFrame", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.Cdecl)>]
extern int private FSDK_FeedFrame(int Tracker, int64 CameraIdx, int Image, int64& FaceCount, [<Out; MarshalAs(UnmanagedType.LPArray)>] int64[] IDs, int64 MaxSizeInBytes);
let FeedFrame(Tracker: int, CameraIdx: int64, Image: int, faceCount: int64 byref, [<Out>] IDs: int64[] byref, MaxSizeInBytes: int64) =
    let ids = Array.create (int MaxSizeInBytes) 0L
    let mutable fc = 0L
    let res = FSDK_FeedFrame(Tracker, CameraIdx, Image, &fc, ids, MaxSizeInBytes)
    res

我在参数列表中尝试了byref的变体，但是结果代码始终表示无效的参数。我是否需要任何特殊的变体以便可以使用此P / Invoke方法？

使用输出参数进行F＃和P / Invoke

0 个答案: