--- product: Chilkat product_version: 11.7.0 language: c language_label: C class: SCard license: bundle deprecated: false reference_html: https://www.chilkatsoft.com/refdoc/c_CkSCardRef.html --- # Chilkat SCard — C — v11.7.0 > Chilkat 11.7.0 · language=c · class=SCard > Other versions: replace `11.7.0` in this URL. Other languages: `https://www.chilkatsoft.com/ai-docs/v/11.7.0//classes/SCard.md`. > Language-wide rules (install, unlock, error model, strings/bytes): `https://www.chilkatsoft.com/ai-docs/v/11.7.0/c/guide.md`. ## Purpose **Communicate directly with smart card readers and cards through PC/SC.** `Chilkat.SCard` is the low-level PC/SC smart card interface for applications that need direct reader and card communication. It supports reader discovery, reader connection, card status checking, APDU transmission, reader-control commands, status-change monitoring, transactions, and diagnostic access to underlying PC/SC errors. Use this class when the application needs APDU-level control rather than a higher-level certificate, minidriver, or PKCS#11 abstraction. **Reader discovery** Enumerate available PC/SC smart card readers and identify the reader the application should use. **Connect to cards** Connect to a reader/card, check card presence and status, and manage the active PC/SC connection. **Transmit APDUs** Send APDU commands directly to the card and receive the raw response bytes and status words. **Reader-control commands** Issue lower-level reader control commands when supported by the reader driver and PC/SC environment. **Status monitoring** Monitor reader or card status changes so applications can detect card insertion, removal, or state changes. **Transactions and diagnostics** Use PC/SC transactions for coordinated card access and inspect detailed error information when reader or card operations fail. **Common pattern:** Establish the PC/SC context, list readers, connect to the selected reader, check card status, transmit APDU commands, process the response bytes, and disconnect when finished. Use `Chilkat.SCard` for direct PC/SC reader and APDU-level work; use `Chilkat.ScMinidriver` for card-minidriver certificate and key-container operations, and `Chilkat.Pkcs11` for PKCS#11 token or HSM sessions. For an extended overview, see [SCard Class Overview](https://www.chilkatsoft.com/scard_class_overview.asp). ## Object creation, unlocking and error handling **Create/Dispose** ```c HCkSCard instance = CkSCard_Create(); // ... CkSCard_Dispose(instance); ``` `HCkSCard CkSCard_Create(void);` Creates an instance of the HCkSCard object and returns a handle ("void \*" pointer). The handle is passed in the 1st argument for the functions listed on this page. `void CkSCard_Dispose(HCkSCard handle);` Objects created by calling CkSCard_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkSCard_Dispose. Call `Global.UnlockBundle` once at the start of the program, before using this or any other Chilkat class. Any string unlocks a fully functional 30-day trial; a purchased unlock code is used in production. See `guide.md` for the exact code in C. ## Members common to every Chilkat class Documented once per language in `common-members.md`; listed here so this page is self-contained. | Property | Signature | Access | Meaning | |---|---|---|---| | `DebugLogFilePath` | `void CkSCard_getDebugLogFilePath(HCkSCard cHandle, HCkString retval); void CkSCard_putDebugLogFilePath(HCkSCard cHandle, const char *newVal); const char *CkSCard_debugLogFilePath(HCkSCard cHandle);` | read/write | If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. | | `LastErrorHtml` | `void CkSCard_getLastErrorHtml(HCkSCard cHandle, HCkString retval); const char *CkSCard_lastErrorHtml(HCkSCard cHandle);` | read-only | Provides HTML-formatted information about the last called method or property. | | `LastErrorText` | `void CkSCard_getLastErrorText(HCkSCard cHandle, HCkString retval); const char *CkSCard_lastErrorText(HCkSCard cHandle);` | read-only | Provides plain text information about the last called method or property. | | `LastErrorXml` | `void CkSCard_getLastErrorXml(HCkSCard cHandle, HCkString retval); const char *CkSCard_lastErrorXml(HCkSCard cHandle);` | read-only | Provides XML-formatted information about the last called method or property. | | `LastMethodSuccess` | `BOOL CkSCard_getLastMethodSuccess(HCkSCard cHandle); void CkSCard_putLastMethodSuccess(HCkSCard cHandle, BOOL newVal);` | read/write | Indicates the success or failure of the most recent method call: `TRUE` means success, `FALSE` means failure. | | `Utf8` | `BOOL CkSCard_getUtf8(HCkSCard cHandle); void CkSCard_putUtf8(HCkSCard cHandle, BOOL newVal);` | read/write | When set to `TRUE`, all `const char *` arguments and return values are interpreted as UTF-8 strings. | | `VerboseLogging` | `BOOL CkSCard_getVerboseLogging(HCkSCard cHandle); void CkSCard_putVerboseLogging(HCkSCard cHandle, BOOL newVal);` | read/write | If set to `TRUE`, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. | | `Version` | `void CkSCard_getVersion(HCkSCard cHandle, HCkString retval); const char *CkSCard_version(HCkSCard cHandle);` | read-only | Version of the component/library, such as "10.1.0" | ## Member index | Member | Kind | Signature | |---|---|---| | `ActiveProtocol` | property, read-only | `void CkSCard_getActiveProtocol(HCkSCard cHandle, HCkString retval); const char *CkSCard_activeProtocol(HCkSCard cHandle);` | | `CardAtr` | property, read-only | `void CkSCard_getCardAtr(HCkSCard cHandle, HCkString retval); const char *CkSCard_cardAtr(HCkSCard cHandle);` | | `ConnectedReader` | property, read-only | `void CkSCard_getConnectedReader(HCkSCard cHandle, HCkString retval); const char *CkSCard_connectedReader(HCkSCard cHandle);` | | `Context` | property, read-only | `void CkSCard_getContext(HCkSCard cHandle, HCkString retval); const char *CkSCard_context(HCkSCard cHandle);` | | `PcscLibPath` | property, read/write | `void CkSCard_getPcscLibPath(HCkSCard cHandle, HCkString retval); void CkSCard_putPcscLibPath(HCkSCard cHandle, const char *newVal); const char *CkSCard_pcscLibPath(HCkSCard cHandle);` | | `ReaderStatus` | property, read-only | `void CkSCard_getReaderStatus(HCkSCard cHandle, HCkString retval); const char *CkSCard_readerStatus(HCkSCard cHandle);` | | `ScardError` | property, read-only | `void CkSCard_getScardError(HCkSCard cHandle, HCkString retval); const char *CkSCard_scardError(HCkSCard cHandle);` | | `BeginTransaction` | method | `BOOL CkSCard_BeginTransaction(HCkSCard cHandle);` | | `CheckStatus` | method | `BOOL CkSCard_CheckStatus(HCkSCard cHandle);` | | `Connect` | method | `BOOL CkSCard_Connect(HCkSCard cHandle, const char *reader, const char *shareMode, const char *preferredProtocol);` | | `Disconnect` | method | `BOOL CkSCard_Disconnect(HCkSCard cHandle, const char *disposition);` | | `EndTransaction` | method | `BOOL CkSCard_EndTransaction(HCkSCard cHandle, const char *disposition);` | | `EstablishContext` | method | `BOOL CkSCard_EstablishContext(HCkSCard cHandle, const char *scope);` | | `FindSmartcards` | method | `BOOL CkSCard_FindSmartcards(HCkSCard cHandle, HCkJsonObject json);` | | `GetAttrib` | method | `BOOL CkSCard_GetAttrib(HCkSCard cHandle, const char *attr, HCkBinData bd);` | | `GetAttribStr` | method | `BOOL CkSCard_GetAttribStr(HCkSCard cHandle, const char *attr, HCkString outStr); const char *CkSCard_getAttribStr(HCkSCard cHandle, const char *attr);` | | `GetAttribUint` | method | `unsigned long CkSCard_GetAttribUint(HCkSCard cHandle, const char *attr);` | | `GetStatusChange` | method | `BOOL CkSCard_GetStatusChange(HCkSCard cHandle, int maxWaitMs, HCkStringTable stReaderNames, HCkJsonObject json);` | | `GetStatusChangeCancel` | method | `BOOL CkSCard_GetStatusChangeCancel(HCkSCard cHandle);` | | `ListReaderGroups` | method | `BOOL CkSCard_ListReaderGroups(HCkSCard cHandle, HCkStringTable readerGroups);` | | `ListReaders` | method | `BOOL CkSCard_ListReaders(HCkSCard cHandle, HCkStringTable st);` | | `Reconnect` | method | `BOOL CkSCard_Reconnect(HCkSCard cHandle, const char *shareMode, const char *preferredProtocol, const char *action);` | | `ReleaseContext` | method | `BOOL CkSCard_ReleaseContext(HCkSCard cHandle);` | | `SendControl` | method | `BOOL CkSCard_SendControl(HCkSCard cHandle, unsigned long controlCode, HCkBinData bdSend, HCkBinData bdRecv);` | | `SendControlHex` | method | `BOOL CkSCard_SendControlHex(HCkSCard cHandle, unsigned long controlCode, const char *sendData, HCkBinData bdRecv);` | | `Transmit` | method | `BOOL CkSCard_Transmit(HCkSCard cHandle, const char *protocolName, HCkBinData bdSend, HCkBinData bdRecv, int maxRecvLen);` | | `TransmitHex` | method | `BOOL CkSCard_TransmitHex(HCkSCard cHandle, const char *protocolName, const char *apduHex, HCkBinData bdRecv, int maxRecvLen);` | ## Properties ### SCard.ActiveProtocol `Chilkat 11.7.0 · c · SCard · ActiveProtocol · property · read-only · since 9.50.87` ```c void CkSCard_getActiveProtocol(HCkSCard cHandle, HCkString retval); const char *CkSCard_activeProtocol(HCkSCard cHandle); ``` The name of the active protocol if connected smart card reader, or an empty string if not connected. Possible values are `T0`, `T1`, `raw`, `undefined`, or if not connected to a reader. ### SCard.CardAtr `Chilkat 11.7.0 · c · SCard · CardAtr · property · read-only · since 9.50.87` ```c void CkSCard_getCardAtr(HCkSCard cHandle, HCkString retval); const char *CkSCard_cardAtr(HCkSCard cHandle); ``` This is the Current ATR of a card in the connected reader. ### SCard.ConnectedReader `Chilkat 11.7.0 · c · SCard · ConnectedReader · property · read-only · since 9.50.87` ```c void CkSCard_getConnectedReader(HCkSCard cHandle, HCkString retval); const char *CkSCard_connectedReader(HCkSCard cHandle); ``` The name of the currently connected smart card reader, or an empty string if not connected. ### SCard.Context `Chilkat 11.7.0 · c · SCard · Context · property · read-only · since 9.50.87` ```c void CkSCard_getContext(HCkSCard cHandle, HCkString retval); const char *CkSCard_context(HCkSCard cHandle); ``` Contains the string `user` or `system` if this object has established a context (by calling EstablishContext). Contains the empty string if no context is established. ### SCard.PcscLibPath `Chilkat 11.7.0 · c · SCard · PcscLibPath · property · read/write · since 9.50.87` ```c void CkSCard_getPcscLibPath(HCkSCard cHandle, HCkString retval); void CkSCard_putPcscLibPath(HCkSCard cHandle, const char *newVal); const char *CkSCard_pcscLibPath(HCkSCard cHandle); ``` For Linux systems only. Specifies the full path of the libpcsclite.so shared lib. This property should only be used if the libpcsclite.so is in a non-standard location or if Chilkat cannot automatically located it. ### SCard.ReaderStatus `Chilkat 11.7.0 · c · SCard · ReaderStatus · property · read-only · since 9.50.87` ```c void CkSCard_getReaderStatus(HCkSCard cHandle, HCkString retval); const char *CkSCard_readerStatus(HCkSCard cHandle); ``` The current status of the connected reader. Possible values are: - `absent` - There is no card in the reader. - `present` - There is a card in the reader, but it has not been moved into position for use. - `swallowed` - There is a card in the reader in position for use. The card is not powered. - `powered` - Power is being provided to the card, but the reader driver is unaware of the mode of the card. - `negotiable` - The card has been reset and is awaiting PTS negotiation. - `specific` - The card has been reset and specific communication protocols have been established. ### SCard.ScardError `Chilkat 11.7.0 · c · SCard · ScardError · property · read-only · since 9.50.87` ```c void CkSCard_getScardError(HCkSCard cHandle, HCkString retval); const char *CkSCard_scardError(HCkSCard cHandle); ``` The last error returned by an underlying PC/SC function. Can be one of the following: - `SCARD_W_REMOVED_CARD` - The smart card has been removed, so that further communication is not possible. - `SCARD_W_RESET_CARD` - The smart card has been reset, so any shared state information is invalid. ... ## Methods ### SCard.BeginTransaction `Chilkat 11.7.0 · c · SCard · BeginTransaction · method · since 9.50.87` ```c BOOL CkSCard_BeginTransaction(HCkSCard cHandle); ``` Establishes a temporary exclusive access mode for doing a series of commands in a transaction. Returns TRUE for success, FALSE for failure. ### SCard.CheckStatus `Chilkat 11.7.0 · c · SCard · CheckStatus · method · since 9.50.87` ```c BOOL CkSCard_CheckStatus(HCkSCard cHandle); ``` Check the current status of the currently connected reader. Calling this method updates the ReaderStatus, ActiveProtocol, and CardAtr properties. If this method returns `FALSE`, none of the properties are updated. Returns TRUE for success, FALSE for failure. ### SCard.Connect `Chilkat 11.7.0 · c · SCard · Connect · method · since 9.50.87` ```c BOOL CkSCard_Connect(HCkSCard cHandle, const char *reader, const char *shareMode, const char *preferredProtocol); ``` Establish a connection to a reader. The `reader` is the name of a reader returned from ListReaders. The `shareMode` can be `shared`, `exclusive`, or `direct`. The `preferredProtocol` can be `0` (valid only if the shareMode = `direct`), `T0`, `T1`, `raw`, or `no_preference`. (No preference is effectively T0 or T1.) If successful, the state of this object instance is that it's connected to the reader. Returns TRUE for success, FALSE for failure. ### SCard.Disconnect `Chilkat 11.7.0 · c · SCard · Disconnect · method · since 9.50.87` ```c BOOL CkSCard_Disconnect(HCkSCard cHandle, const char *disposition); ``` Terminates a connection with a reader. The `disposition` can be one of the following values: - `leave`: Do nothing. - `reset`: Reset the card (warm reset). - `unpower`: Power down the card (cold reset). - `eject`: Eject the card. Returns TRUE for success, FALSE for failure. ### SCard.EndTransaction `Chilkat 11.7.0 · c · SCard · EndTransaction · method · since 9.50.87` ```c BOOL CkSCard_EndTransaction(HCkSCard cHandle, const char *disposition); ``` Ends a previously begun transaction. The `disposition` is the action to be taken on the reader, and can be `leave` which is to do nothing, `reset`, `unpower`, or `eject`. Returns TRUE for success, FALSE for failure. ### SCard.EstablishContext `Chilkat 11.7.0 · c · SCard · EstablishContext · method · since 9.5.0.87` ```c BOOL CkSCard_EstablishContext(HCkSCard cHandle, const char *scope); ``` Creates an Application Context to the PC/SC Resource Manager. This must be the first WinSCard function called in a PC/SC application. The `scope` can be `user` or `system`. After calling, this object will have context and all other methods will use the established context. The `Context` property will hold the value `user` or `system` if context was established, or will be empty if no context was established. Returns TRUE for success, FALSE for failure. ### SCard.FindSmartcards `Chilkat 11.7.0 · c · SCard · FindSmartcards · method · since 9.50.87` ```c BOOL CkSCard_FindSmartcards(HCkSCard cHandle, HCkJsonObject json); ``` Returns JSON containing information about the smartcards currently inserted into readers. Returns TRUE for success, FALSE for failure. ### SCard.GetAttrib `Chilkat 11.7.0 · c · SCard · GetAttrib · method · since 9.50.87` ```c BOOL CkSCard_GetAttrib(HCkSCard cHandle, const char *attr, HCkBinData bd); ``` Get an attribute from the IFD Handler (reader driver). The `attr` can be one of the following: - `ASYNC_PROTOCOL_TYPES` - `ATR_STRING` - `CHANNEL_ID` - `CHARACTERISTICS` - `CURRENT_BWT` - `CURRENT_CLK` - `CURRENT_CWT` - `CURRENT_D` - `CURRENT_EBC_ENCODING` - `CURRENT_F` - `CURRENT_IFSC` - `CURRENT_IFSD` - `CURRENT_IO_STATE` - `CURRENT_N` - `CURRENT_PROTOCOL_TYPE` - `CURRENT_W` - `DEFAULT_CLK` - `DEFAULT_DATA_RATE` - `DEVICE_FRIENDLY_NAME` - `DEVICE_IN_USE` - `DEVICE_SYSTEM_NAME` - `DEVICE_UNIT` - `ESC_AUTHREQUEST` - `ESC_CANCEL` - `ESC_RESET` - `EXTENDED_BWT` - `ICC_INTERFACE_STATUS` - `ICC_PRESENCE` - `ICC_TYPE_PER_ATR` - `MAX_CLK` - `MAX_DATA_RATE` - `MAX_IFSD` - `MAXINPUT` - `POWER_MGMT_SUPPORT` - `SUPRESS_T1_IFS_REQUEST` - `SYNC_PROTOCOL_TYPES` - `USER_AUTH_INPUT_DEVICE` - `USER_TO_CARD_AUTH_DEVICE` - `VENDOR_IFD_SERIAL_NO` - `VENDOR_IFD_TYPE` - `VENDOR_IFD_VERSION` - `VENDOR_NAME` The attribute data is returned in `bd`. Returns TRUE for success, FALSE for failure. ### SCard.GetAttribStr `Chilkat 11.7.0 · c · SCard · GetAttribStr · method · since 9.50.87` ```c BOOL CkSCard_GetAttribStr(HCkSCard cHandle, const char *attr, HCkString outStr); const char *CkSCard_getAttribStr(HCkSCard cHandle, const char *attr); ``` Get a string typed attribute from the IFD Handler (reader driver). The `attr` can be one of the following, but should be limited to the particular attributes that return string values. - `ASYNC_PROTOCOL_TYPES` - `ATR_STRING` - `CHANNEL_ID` - `CHARACTERISTICS` - `CURRENT_BWT` - `CURRENT_CLK` - `CURRENT_CWT` - `CURRENT_D` - `CURRENT_EBC_ENCODING` - `CURRENT_F` - `CURRENT_IFSC` - `CURRENT_IFSD` - `CURRENT_IO_STATE` - `CURRENT_N` - `CURRENT_PROTOCOL_TYPE` - `CURRENT_W` - `DEFAULT_CLK` - `DEFAULT_DATA_RATE` - `DEVICE_FRIENDLY_NAME` - `DEVICE_IN_USE` - `DEVICE_SYSTEM_NAME` - `DEVICE_UNIT` - `ESC_AUTHREQUEST` - `ESC_CANCEL` - `ESC_RESET` - `EXTENDED_BWT` - `ICC_INTERFACE_STATUS` - `ICC_PRESENCE` - `ICC_TYPE_PER_ATR` - `MAX_CLK` - `MAX_DATA_RATE` - `MAX_IFSD` - `MAXINPUT` - `POWER_MGMT_SUPPORT` - `SUPRESS_T1_IFS_REQUEST` - `SYNC_PROTOCOL_TYPES` - `USER_AUTH_INPUT_DEVICE` - `USER_TO_CARD_AUTH_DEVICE` - `VENDOR_IFD_SERIAL_NO` - `VENDOR_IFD_TYPE` - `VENDOR_IFD_VERSION` - `VENDOR_NAME` Returns TRUE for success, FALSE for failure. ### SCard.GetAttribUint `Chilkat 11.7.0 · c · SCard · GetAttribUint · method · since 9.50.87` ```c unsigned long CkSCard_GetAttribUint(HCkSCard cHandle, const char *attr); ``` Get an unsigned integer typed attribute from the IFD Handler (reader driver). The `attr` can be one of the following, but should be limited to the particular attributes that return unsigned integer values. - `ASYNC_PROTOCOL_TYPES` - `ATR_STRING` - `CHANNEL_ID` - `CHARACTERISTICS` - `CURRENT_BWT` - `CURRENT_CLK` - `CURRENT_CWT` - `CURRENT_D` - `CURRENT_EBC_ENCODING` - `CURRENT_F` - `CURRENT_IFSC` - `CURRENT_IFSD` - `CURRENT_IO_STATE` - `CURRENT_N` - `CURRENT_PROTOCOL_TYPE` - `CURRENT_W` - `DEFAULT_CLK` - `DEFAULT_DATA_RATE` - `DEVICE_FRIENDLY_NAME` - `DEVICE_IN_USE` - `DEVICE_SYSTEM_NAME` - `DEVICE_UNIT` - `ESC_AUTHREQUEST` - `ESC_CANCEL` - `ESC_RESET` - `EXTENDED_BWT` - `ICC_INTERFACE_STATUS` - `ICC_PRESENCE` - `ICC_TYPE_PER_ATR` - `MAX_CLK` - `MAX_DATA_RATE` - `MAX_IFSD` - `MAXINPUT` - `POWER_MGMT_SUPPORT` - `SUPRESS_T1_IFS_REQUEST` - `SYNC_PROTOCOL_TYPES` - `USER_AUTH_INPUT_DEVICE` - `USER_TO_CARD_AUTH_DEVICE` - `VENDOR_IFD_SERIAL_NO` - `VENDOR_IFD_TYPE` - `VENDOR_IFD_VERSION` - `VENDOR_NAME` Returns 0xFFFFFFFF on failure. ### SCard.GetStatusChange `Chilkat 11.7.0 · c · SCard · GetStatusChange · method · since 9.50.87` ```c BOOL CkSCard_GetStatusChange(HCkSCard cHandle, int maxWaitMs, HCkStringTable stReaderNames, HCkJsonObject json); ``` Blocks execution until the current availability of the cards in a specific set of readers changes. This function receives a list of reader names in `stReaderNames`. It then blocks waiting for a change in state to occur for a maximum blocking time of `maxWaitMs` (in milliseconds) or forever if 0 is used. Information about the current reader states and which reader(s) changed is returned in `json`. See the example below for more information. To wait for a reader event (reader added or removed) you may use the special reader name `\\?PnP?\Notification`. To cancel the ongoing call, call Cancel(). The `stReaderNames` contains the reader names to check. The `json` is empty on input, and if the call returns success contains information about the state (after the event change) of each reader. Returns TRUE for success, FALSE for failure. Async variant: `GetStatusChangeAsync` — same arguments, returns a `Task` (see Async variants below). ### SCard.GetStatusChangeCancel `Chilkat 11.7.0 · c · SCard · GetStatusChangeCancel · method · since 9.50.87` ```c BOOL CkSCard_GetStatusChangeCancel(HCkSCard cHandle); ``` Cancels an ongoing GetStatusChange method call. This would be called from a separate thread in your application if GetStatusChange was called synchronously. Returns TRUE for success, FALSE for failure. ### SCard.ListReaderGroups `Chilkat 11.7.0 · c · SCard · ListReaderGroups · method · since 9.50.87` ```c BOOL CkSCard_ListReaderGroups(HCkSCard cHandle, HCkStringTable readerGroups); ``` Returns a list of currently available reader groups on the system. The reader groups are returned in `readerGroups`. Returns TRUE for success, FALSE for failure. ### SCard.ListReaders `Chilkat 11.7.0 · c · SCard · ListReaders · method · since 9.50.87` ```c BOOL CkSCard_ListReaders(HCkSCard cHandle, HCkStringTable st); ``` Returns a list of currently available readers on the system. Returns TRUE for success, FALSE for failure. ### SCard.Reconnect `Chilkat 11.7.0 · c · SCard · Reconnect · method · since 9.50.87` ```c BOOL CkSCard_Reconnect(HCkSCard cHandle, const char *shareMode, const char *preferredProtocol, const char *action); ``` Reestablishes a connection to a reader that was previously connected to using Connect(). In a multi application environment it is possible for an application to reset the card in shared mode. When this occurs any other application trying to access certain commands will be returned the value SCARD_W_RESET_CARD. When this occurs Reconnect() must be called in order to acknowledge that the card was reset and allow it to change its state accordingly. The `shareMode` can be `shared`, `exclusive`, or `direct`. The `preferredProtocol` can be `0` (valid only if the shareMode = `direct`), `T0`, `T1`, `raw`, or `no_preference`. (No preference is effectively T0 or T1.) The `action` is the desired action taken on the card/reader. It can be `leave`, `reset`, `unpower`, or `eject`. If successful, the state of this object instance is that it's connected to the reader. Returns TRUE for success, FALSE for failure. ### SCard.ReleaseContext `Chilkat 11.7.0 · c · SCard · ReleaseContext · method · since 9.50.87` ```c BOOL CkSCard_ReleaseContext(HCkSCard cHandle); ``` Destroys a communication context to the PC/SC Resource Manager. This must be the last function called in a PC/SC application. Returns TRUE for success, FALSE for failure. ### SCard.SendControl `Chilkat 11.7.0 · c · SCard · SendControl · method · since 9.50.87` ```c BOOL CkSCard_SendControl(HCkSCard cHandle, unsigned long controlCode, HCkBinData bdSend, HCkBinData bdRecv); ``` Sends a command directly to the IFD Handler (reader driver) to be processed by the reader. This is useful for creating client side reader drivers for functions like PIN pads, biometrics, or other extensions to the normal smart card reader that are not normally handled by PC/SC. The command data is sent in `bdSend`. The response is written to `bdRecv`. Returns TRUE for success, FALSE for failure. ### SCard.SendControlHex `Chilkat 11.7.0 · c · SCard · SendControlHex · method · since 9.50.87` ```c BOOL CkSCard_SendControlHex(HCkSCard cHandle, unsigned long controlCode, const char *sendData, HCkBinData bdRecv); ``` Sends a command directly to the IFD Handler (reader driver) to be processed by the reader. This is useful for creating client side reader drivers for functions like PIN pads, biometrics, or other extensions to the normal smart card reader that are not normally handled by PC/SC. The command data is provided as a hex string in `sendData`. The response is written to `bdRecv`. Returns TRUE for success, FALSE for failure. ### SCard.Transmit `Chilkat 11.7.0 · c · SCard · Transmit · method · since 9.50.87` ```c BOOL CkSCard_Transmit(HCkSCard cHandle, const char *protocolName, HCkBinData bdSend, HCkBinData bdRecv, int maxRecvLen); ``` Sends an APDU to the smart card contained in the currently connected reader. The `protocolName` can be `T0`, `T1`, or `raw`. The APDU to be sent is contained in `bdSend`. The response from the card is contained in `bdRecv`. The `maxRecvLen` is the maximum response size (in bytes) willing to be accepted. Returns TRUE for success, FALSE for failure. ### SCard.TransmitHex `Chilkat 11.7.0 · c · SCard · TransmitHex · method · since 9.50.87` ```c BOOL CkSCard_TransmitHex(HCkSCard cHandle, const char *protocolName, const char *apduHex, HCkBinData bdRecv, int maxRecvLen); ``` Sends an APDU to the smart card contained in the currently connected reader. The `protocolName` can be `T0`, `T1`, or `raw`. The APDU (in hexadecimal) to be sent is passed in `apduHex`. The response from the card is contained in `bdRecv`. The `maxRecvLen` is the maximum response size (in bytes) willing to be accepted. Returns TRUE for success, FALSE for failure. ## Events and callbacks This binding delivers progress information through callbacks (AbortCheck, PercentDone, ProgressInfo, TaskCompleted) rather than events. See `guide.md` for how to attach them in C. ## Async variants Each returns a `Task` instead of the result and takes the same arguments as the synchronous method; run the task, wait for `Finished`, then read the result from the task. No new Async methods are added from 11.7.0 on. ```c HCkTask CkSCard_GetStatusChangeAsync(HCkSCard cHandle, int maxWaitMs, HCkStringTable stReaderNames, HCkJsonObject json); ``` ## Related classes [`BinData`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/c/classes/BinData.md), [`JsonObject`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/c/classes/JsonObject.md), [`StringTable`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/c/classes/StringTable.md)