// Database Functions
/// <summary>
/// List the reader groups.
/// </summary>
/// <param name="aReaderGroupsList">List of reader groups</param>
/// <returns></returns>
public int ListReaderGroups(IList aReaderGroupsList)
{
// Sanity Check
if (this.m_fDisposed)
{
throw new ObjectDisposedException(base.GetType().FullName);
}
// Sanity Check
if (this.m_hContext == IntPtr.Zero)
{
throw new InvalidOperationException();
}
int nRet = 0;
IntPtr ptrRMgrMem = IntPtr.Zero;
uint nMax = uint.MaxValue;
uint nErrCode = WinSCard.SCardListReaderGroups(this.m_hContext, ref ptrRMgrMem, ref nMax);
// Success
//if (nErrCode == 0)
if (nErrCode == (uint)SCardReturnValues.SCARD_S_SUCCESS)
{
string text = Marshal.PtrToStringAuto(ptrRMgrMem, (int)nMax);
nRet = this._SplitMultiString(text, aReaderGroupsList);
nErrCode = WinSCard.SCardFreeMemory(this.m_hContext, ptrRMgrMem);
return(nRet);
}
// Error
//if (nErrCode == 2148532270)
if (nErrCode == (uint)SCardReturnValues.SCARD_E_NO_READERS_AVAILABLE)
{
return(0);
}
// Exception
//SCardException.RaiseWin32ResponseCode(nErrCode);
return(nRet);
}
/// <summary>
/// List the installed readers within the given list of groups.
/// </summary>
/// <param name="vsGroups">List of reader groups</param>
/// <param name="aReadersList">Provided list object</param>
/// <returns></returns>
public int ListReaders(string[] vsGroups, IList aReadersList)
{
// Sanity Check
if (this.m_fDisposed)
{
throw new ObjectDisposedException(base.GetType().FullName);
}
// A handle to the context had to be established prior to this.
// (i.e. by calling EstablishContext)
if (this.m_hContext == IntPtr.Zero)
{
throw new InvalidOperationException();
}
// Assume no readers yet
int nReaders = 0;
string text = null;
// If a list of readers groups was provided then concatenate them
// into a multi-string. If not then all reader groups will be read.
if ((vsGroups != null) && (vsGroups.Length > 0))
{
string[] textArray = vsGroups;
for (int nIter = 0; nIter < textArray.Length; nIter++)
{
string strTemp = textArray[nIter];
text = text + strTemp;
text = text + '\0';
}
text = text + '\0';
}
// NULL pointer - indicates to allocate the buffer internally.
IntPtr ptrMem = IntPtr.Zero;
// Autoallocate: SCARD_AUTOALLOCATE (which is -1). See Winscard.h within the DDK.
uint nMax = uint.MaxValue;
// List the reader names within the given groups.
//
// If pointer to the readers list (3rd parm) is NULL, SCardListReaders ignores the buffer length supplied
// in the 4th parm, writes the length of the buffer that would have been returned if this parameter had not
// been NULL to that passed in pointer, and returns a success code.
//
// The 4th parameter receives the actual length of the multi-string structure, including all trailing null
// characters. If the buffer length is specified as SCARD_AUTOALLOCATE, then mszReaders is converted to
// a pointer to a byte pointer, and receives the address of a block of memory containing the multi-string
// structure. This block of memory must be deallocated with SCardFreeMemory.
uint nErrCode = WinSCard.SCardListReaders(this.m_hContext, text, ref ptrMem, ref nMax);
// If the call returned OK then can interpret the results.
if (nErrCode == (uint)SCardReturnValues.SCARD_S_SUCCESS)
{
// Marshall the list of readers to a string
string sReaders = Marshal.PtrToStringAuto(ptrMem, (int)nMax);
// Split the string into the ArrayList object provided by caller.
nReaders = this._SplitMultiString(sReaders, aReadersList);
// Free Autoallocate
nErrCode = WinSCard.SCardFreeMemory(this.m_hContext, ptrMem);
// Return the number of items in the ArrayList.
return(nReaders);
}
// Not successfully read
if (nErrCode == (uint)SCardReturnValues.SCARD_E_NO_READERS_AVAILABLE)
{
return(0);
}
// Report Error
//SCardException.RaiseWin32ResponseCode(nErrCode);
return(nReaders);
}