Question

我是新手to.net，我想确定是否使用winscard的SCardGetStatusChange检测到或删除了卡片。但它返回retcode = -2146435063，转换为Hex时会给我0x80100009 = SCARD_E_UNKNOWN_READER。我只是根据pinvoke.net

编写代码

以下是我的代码示例

def find_area(r):
    s = math.sqrt(2)
    sidesquare = s * r * 2 / 2
    square = (sidesquare * 2) ** 2
    circle = 3.14 * r ** 2
    area = circle - square
    return area

以我的形式。

Public Structure SCARDREADER_STATE
    Public szReader As String
    Public pvUserData As IntPtr
    Public dwCurrentState As Integer
    Public dwEventState As Integer
    Public cbAtr As Integer
    Public rgbAtr() As Byte
End Structure

<DllImport(winscarddll, CharSet:=CharSet.Ansi, EntryPoint:="SCardGetStatusChangeA")>
Public Shared Function SCardGetStatusChange(ByVal hContext As IntPtr, ByVal dwTime As Integer, ByRef rgReaderState As SCARDREADER_STATE(), ByVal cReaders As Integer) As Integer
End Function

输出

t RET = -2146435063 读者：ACS ACR1222 3S PICC读卡器PICC 0 失败

Answer 1

对于未来的研究人员/开发人员。

在SCardGetStatusChange中，我刚刚将SCardReaderState（）更改为SCardReader

<DllImport(winscarddll, EntryPoint:="SCardGetStatusChangeA", CharSet:=CharSet.Ansi)>
Public Shared Function SCardGetStatusChange(ByVal hContext As IntPtr, ByVal dwTime As Integer, ByRef rgReaderState As SCARDREADER_STATE, ByVal cReaders As Integer) As Integer
End Function

然后在rgbAtr初始化中添加<MarshalAs(UnmanagedType.ByValArray, SizeConst:=36)>。

希望这会有所帮助。

SCardGetStatusChange Winscard中的未知读者

1 个答案: