C＃SCardGetStatusChange（）检查智能卡状态

Question

我想检测智能卡的状态以查看是否插入或拔出了智能卡
为此，我使用智能卡在这里读取代码

我发现可以检测到SCardGetStatusChange函数，但是不知道如何使用。 这是我的添加代码

[DllImport("winscard.dll")]
    public static extern int SCardGetStatusChange(int hContext,uint dwTimeout,[In, Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex=3)]SCARD_READERSTATE[] rgReaderState,uint cReaders);

public struct SCARD_READERSTATE
    {
        [MarshalAs(UnmanagedType.LPTStr)]
        public string szReader;
        public IntPtr pvUserData;
        public uint dwCurrentState;
        public uint dwEventState;
        public uint cbAtr;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 36)]
        public byte[] rgbAtr;
    }
SCARD_READERSTATE[] rs = new SCARD_READERSTATE[1];
rs[0].szReader = ReaderList;
rs[0].dwCurrentState = SCARD_STATE_UNAWARE;
int result = SCardGetStatusChange(ContextHandle, 1000, rs, 2);

但是结果总是一样，我不知道什么是错误的参数。

Answer 1

这是一个可以满足您需求的程序，您可以根据需要调整代码。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Text;

namespace SimpleSmartCardTester
{
    static class Program
    {
        public static class SmartCardScope
        {
            public static readonly Int32 User = 0;
            public static readonly Int32 Terminal = 1;
            public static readonly Int32 System = 2;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct SmartCardReaderState
        {
            public string cardReaderString;
            public IntPtr userDataPointer;
            public UInt32 currentState;
            public UInt32 eventState;
            public UInt32 atrLength;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 36)]
            public byte[] ATR;
        }

        public static class SmartCardState
        {
            public static readonly UInt32 Unaware = 0x00000000;
            public static readonly UInt32 Ignore = 0x00000001;
            public static readonly UInt32 Changed = 0x00000002;
            public static readonly UInt32 Unknown = 0x00000004;
            public static readonly UInt32 Unavailable = 0x00000008;
            public static readonly UInt32 Empty = 0x00000010;
            public static readonly UInt32 Present = 0x00000020;
            public static readonly UInt32 Atrmatch = 0x00000040;
            public static readonly UInt32 Exclusive = 0x00000080;
            public static readonly UInt32 Inuse = 0x00000100;
            public static readonly UInt32 Mute = 0x00000200;
            public static readonly UInt32 Unpowered = 0x00000400;
        }

        public const int SCARD_S_SUCCESS = 0;

        [DllImport("winscard.dll")]
        internal static extern int SCardEstablishContext(Int32 dwScope, IntPtr pReserved1, IntPtr pReserved2, out Int32 hContext);

        [DllImport("winscard.dll", EntryPoint = "SCardListReadersA", CharSet = CharSet.Ansi)]
        internal static extern int SCardListReaders(Int32 hContext, byte[] cardReaderGroups, byte[] readersBuffer, out UInt32 readersBufferLength);

        [DllImport("winscard.dll")]
        internal static extern int SCardGetStatusChange(Int32 hContext, UInt32 timeoutMilliseconds, [In, Out] SmartCardReaderState[] readerStates, Int32 readerCount);

        private static List<string> ParseReaderBuffer(byte[] buffer)
        {
            var str = Encoding.ASCII.GetString(buffer);
            if (string.IsNullOrEmpty(str)) return new List<string>();
            return new List<string>(str.Split(new char[] { '\0' }, StringSplitOptions.RemoveEmptyEntries));
        }

        private static bool CheckIfFlagsSet(UInt32 mask, params UInt32[] flagList)
        {
            foreach (UInt32 flag in flagList)
            {
                if (IsFlagSet(mask, flag)) return true;
            }

            return false;
        }

        private static bool IsFlagSet(UInt32 mask, UInt32 flag)
        {
            return ((flag & mask) > 0);
        }

        static void Main()
        {
            int context = 0;

            Console.WriteLine("Checking card readers...)");
            var result = SCardEstablishContext(SmartCardScope.User, IntPtr.Zero, IntPtr.Zero, out context);
            if (result != SCARD_S_SUCCESS) throw new Exception("Smart card error: " + result.ToString());

            uint bufferLength = 10000;
            byte[] readerBuffer = new byte[bufferLength];

            result = SCardListReaders(context, null, readerBuffer, out bufferLength);
            if (result != SCARD_S_SUCCESS) throw new Exception("Smart card error: " + result.ToString());

            var readers = ParseReaderBuffer(readerBuffer);

            Console.WriteLine("{0} Card Reader(s)", readers.Count);
            if (readers.Any())
            {
                var readerStates = readers.Select(cardReaderName => new SmartCardReaderState() { cardReaderString = cardReaderName }).ToArray();

                result = SCardGetStatusChange(context, 1000, readerStates, readerStates.Length);
                if (result != SCARD_S_SUCCESS) throw new Exception("Smart card error: " + result.ToString());

                readerStates.ToList().ForEach(readerState => Console.WriteLine("Reader: {0}, State: {1}", readerState.cardReaderString,
                    CheckIfFlagsSet(readerState.eventState, SmartCardState.Present, SmartCardState.Atrmatch) ? "Card Present" : "Card Absent"));
            }

            Console.ReadLine();
        }
    }
}