C# SCardTrasmit返回空接收字节数组

我正在使用ACS阅读器和NFC标签进行c#PC/SC实现

我已将SCardTransmit原型化如下：

[DllImport("winscard.dll")]
public static extern int SCardTransmit (Int32 hCard, ref SCARD_IO_REQUEST pioSendRequest, byte[] SendBuff, Int32 SendBuffLen, ref SCARD_IO_REQUEST pioRecvRequest, byte[] RecvBuff, out Int32 RecvBuffLen);

我有以下代码：

        SCard.SCARD_IO_REQUEST ioRequest = new SCard.SCARD_IO_REQUEST();
        ioRequest.dwProtocol = Protocol; // Is going to be T=1
        ioRequest.cbPciLength = 8;

        byte[] cmdBytes = new byte[] { 0xFF, 0xCA, 0x00, 0x00, 0x00 };
        byte[] rcvBytes = new byte[10];
        int rcvLenght = 0;

        retCode = SCard.SCardTransmit(Handle,
            ref ioRequest, cmdBytes, cmdBytes.Length,
            ref ioRequest, rcvBytes, out rcvLenght);

        if (retCode != SCard.SCARD_S_SUCCESS)
            throw new Exception("Failed querying tag UID: " + retCode);

所有（未显示）初始化的东西似乎工作良好，我可以成功地获得标签的ATR

现在，运行这段代码，我得到一个成功的返回代码，我收到一个一致的received bytes Length值，但是Corresponding byte数组是空的（零）

有人能给我一些建议吗

---

谢谢。

SCardTransmit的原型很可能就是问题所在。我会这样写：

[DllImport("winscard.dll")]
public static extern uint SCardTransmit(Int32 hCard, SCARD_IO_REQUEST pioSendPci, [In] byte[] pbSendBuffer, uint cbSendLength, SCARD_IO_REQUEST pioRecvPci, [In, Out] byte[] pbRecvBuffer, ref uint pcbRecvLength);

主要区别在于倒数第二个参数

pbRecvBuffer

，它是用属性

In

和

Out

声明的