TAPI functions do return zero if the function succeeds or a negative error number if an error occurs. Everytime a TAPI function called by hbTapi Components returned a negative error number, the error is indicated as a Delphi exception. Read this documentation of a function or property to be aware of possiblie occuring exceptions (errors).

Some TAPI functions are workin in an asynchronous mater. They return immideatly with an error or positive result - the request id. The real result of the fnction is then returned later within a LINE_REPLY message. When you're using hbTapi Components in an asynchronous manner, you have to use the LastRequestID property and the OnTapiReply event to get the result of an asynchron function. Otherwise an error is immidiatly indicated as an EhbTapiError exception.

The EhbTapiError class has two sub-properties:

ErrorCode
Message

Declaration

Example

See Also

ThbTapiLine.OnTapiReply, ThbTapiLine.OnTapiTimeout, ThbTapiLine.Options.SyncMode, ThbTapiPhone.OnTapiReply, ThbTapiPhone.Options.SyncMode, ThbTapiPhone.OnTapiTimeout

ErrorCode (DWord)

The ErrorCode member holds the numeric value of the error. This uses one of the LINEERR_ or PHONERR_ constants:

Constant	Meaning
LINEERR_ADDRESSBLOCKED	The specified address is blocked from being dialed on the specified call.
LINEERR_ADDRESSBLOCKED	The target call address has call blocking enabled.
LINEERR_ALLOCATED	The line cannot be opened due to a persistent condition, such as that of a serial port being exclusively opened by another process.
LINEERR_BADDEVICEID	The specified device identifier or line device identifier (such as in a dwDeviceID parameter) is invalid or out of range.
LINEERR_BEARERMODEUNAVAIL	The bearer mode member in LINECALLPARAMS is invalid, the bearer mode specified in LINECALLPARAMS is not available, or the call's bearer mode cannot be changed to the specified bearer mode.
LINEERR_BILLINGREJECTED	The billing mode of the call was rejected.
LINEERR_CALLUNAVAIL	All call appearances on the specified address are currently in use.
LINEERR_COMPLETIONOVERRUN	The maximum number of outstanding call completions has been exceeded.
LINEERR_CONFERENCEFULL	The maximum number of parties for a conference has been reached, or the requested number of parties cannot be satisfied.
LINEERR_DIALBILLING	The dialable address parameter contains dialing control characters that are not processed by the service provider.
LINEERR_DIALDIALTONE	The dialable address parameter contains dialing control characters that are not processed by the service provider.
LINEERR_DIALPROMPT	The dialable address parameter contains dialing control characters that are not processed by the service provider.
LINEERR_DIALQUIET	The dialable address parameter contains dialing control characters that are not processed by the service provider.
LINEERR_DIALVOICEDETECT	Use of the ":" dial modifier is not supported. This value is exposed only to applications that negotiate a TAPI version of 2.0 or higher.
LINEERR_DISCONNECTED	The call has been disconnected. This value is exposed only to applications that negotiate a TAPI version of 2.2 or higher.
LINEERR_INCOMPATIBLEAPIVERSION	The application requested a TAPI version or version range that is either incompatible with, or cannot be supported by, the Telephony API implementation and the corresponding service provider.
LINEERR_INCOMPATIBLEEXTVERSION	The application requested an extension version range that is either invalid or cannot be supported by the corresponding service provider.
LINEERR_INIFILECORRUPT	The telephon.ini file cannot be read or understood properly by TAPI because of internal inconsistencies or formatting problems. For example, the [Locations], [Cards], or [Countries] section of the telephon.ini file may be corrupted or inconsistent.
LINEERR_INUSE	The line device is in use and cannot currently be configured, allow a party to be added, allow a call to be answered, allow a call to be placed, or allow a call to be transferred.
LINEERR_INVALADDRESS	A specified address is either invalid or not allowed. If invalid, the address contains invalid characters or digits, or the destination address contains dialing control characters (W, @, $, or ?) that are not supported by the service provider. If not allowed, the specified address is either not assigned to the specified line or is not valid for address redirection.
LINEERR_INVALADDRESSID	The specified address identifier is either invalid or out of range.
LINEERR_INVALADDRESSMODE	The specified address mode is invalid.
LINEERR_INVALADDRESSSTATE	The specified address state contains one or more bits that are not LINEADDRESSSTATE_ constants.
LINEERR_INVALADDRESSTYPE	The application referenced an address type that is not valid. This value is exposed only to applications that negotiate a TAPI version of 3.0 or higher.
LINEERR_INVALAGENTACTIVITY	The specified agent activity is not valid.
LINEERR_INVALAGENTACTIVITY	The application invoking this operation is the target of the indirect handoff. That is, TAPI has determined that the calling application is also the highest priority application for the given media type. This value is exposed only to applications that negotiate a TAPI version of 2.0 or higher.
LINEERR_INVALAGENTGROUP	The specified agent group information is not valid or contains errors. The requested action has not been carried out.
LINEERR_INVALAGENTGROUP	The application referenced an agent group that is not valid. This value is exposed only to applications that negotiate a TAPI version of 2.0 or higher.
LINEERR_INVALAGENTID	The specified agent identifier is invalid.
LINEERR_INVALAGENTID	An invalid agent identifier was used. This value is exposed only to applications that negotiate a TAPI version of 2.0 or higher.
LINEERR_INVALAGENTSESSIONSTATE	The agent session state is invalid. This value is exposed only to applications that negotiate a TAPI version of 2.2 or higher.
LINEERR_INVALAGENTSKILL	The skill group entered is invalid.
LINEERR_INVALAGENTSTATE	The specified agent state is not valid or contains errors. No changes have been made to the agent state of the specified address.
LINEERR_INVALAGENTSTATE	The application referenced an agent state that is not valid. This value is exposed only to applications that negotiate a TAPI version of 2.0 or higher.
LINEERR_INVALAGENTSUPERVISOR	The agent supervisor indicator is invalid.
LINEERR_INVALAPPHANDLE	The application handle (such as specified by a hLineApp parameter) or the appliction registration handle is invalid.
LINEERR_INVALAPPNAME	The specified application name is invalid. If an application name is specified by the application, it is assumed that the string does not contain any non-displayable characters, and is zero-terminated.
LINEERR_INVALBEARERMODE	The specified bearer mode is invalid.
LINEERR_INVALCALLCOMPLMODE	The specified completion is invalid.
LINEERR_INVALCALLHANDLE	The specified call handle is not valid. For example, the handle is not NULL but does not belong to the given line. In some cases, the specified call device handle is invalid.
LINEERR_INVALCALLPARAMS	The specified call parameters are invalid.
LINEERR_INVALCALLPRIVILEGE	The specified call privilege parameter is invalid.
LINEERR_INVALCALLSELECT	The specified select parameter is invalid.
LINEERR_INVALCALLSTATE	The current state of a call is not in a valid state for the requested operation.
LINEERR_INVALCALLSTATELIST	The specified call state list is invalid.
LINEERR_INVALCARD	The permanent card identifier specified in dwCard could not be found in any entry in the [Cards] section in the registry.
LINEERR_INVALCOMPLETIONID	The completion identifier is invalid.
LINEERR_INVALCONFCALLHANDLE	The specified call handle for the conference call is invalid or is not a handle for a conference call.
LINEERR_INVALCONSULTCALLHANDLE	The specified consultation call handle is invalid.
LINEERR_INVALCOUNTRYCODE	The specified country code is invalid.
LINEERR_INVALDEVICECLASS	The line device has no associated device for the given device class, or the specified line does not support the indicated device class.
LINEERR_INVALDEVICEHANDLE	The line device handle is invalid.
LINEERR_INVALDIALPARAMS	The dialing parameters are invalid.
LINEERR_INVALDIGITLIST	The specified digit list is invalid.
LINEERR_INVALDIGITMODE	The specified digit mode is invalid.
LINEERR_INVALDIGITS	The specified termination digits are not valid.
LINEERR_INVALEXTVERSION	The service provider extension version number is invalid.
LINEERR_INVALFEATURE	The dwFeature parameter is invalid.
LINEERR_INVALFEATURE	The application invoked a feature that is not available on this line.
LINEERR_INVALGROUPID	The specified group identifier is invalid.
LINEERR_INVALLINEHANDLE	The specified call, device, line device, or line handle is invalid.
LINEERR_INVALLINESTATE	The device configuration may not be changed in the current line state. The line may be in use by another application or a dwLineStates parameter contains one or more bits that are not LINEDEVSTATE_ constants. The LINEERR_INVALLINESTATE value can also indicate that the device is DISCONNECTED or OUTOFSERVICE. These states are indicated by setting the bits corresponding to the LINEDEVSTATUSFLAGS_CONNECTED and LINEDEVSTATUSFLAGS_INSERVICE values to 0 in the dwDevStatusFlags member of the LINEDEVSTATUS structure returned by the lineGetLineDevStatus function.
LINEERR_INVALLOCATION	The permanent location identifier specified in dwLocation could not be found in any entry in the [Locations] section in the registry.
LINEERR_INVALMEDIALIST	The specified media list is invalid.
LINEERR_INVALMEDIAMODE	The list of media types (modes) to be monitored contains invalid information, the specified media type parameter is invalid, or the service provider does not support the specified media type. The media types supported on the line are listed in the dwMediaModes member in the LINEDEVCAPS structure.
LINEERR_INVALMESSAGEID	The number given in dwMessageID is outside the range specified by the dwNumCompletionMessages member in the LINEADDRESSCAPS structure.
LINEERR_INVALPARAM	A parameter or structure that a parameter points to contains invalid information, a country code is invalid, a window handle is invalid, or the specified forward list parameter contains invalid information.
LINEERR_INVALPARKID	The park identifier is invalid.
LINEERR_INVALPARKMODE	The specified park mode is invalid.
LINEERR_INVALPASSWORD	The specified password is not correct and the requested action has not been carried out.
LINEERR_INVALPASSWORD	The application used an invalid password. This value is exposed only to applications that negotiate a TAPI version of 2.0 or higher.
LINEERR_INVALPOINTER	One or more of the specified pointer parameters (such as lpCallList, lpdwAPIVersion, lpExtensionID, lpdwExtVersion, lphIcon, lpLineDevCaps, and lpToneList) are invalid, or a required pointer to an output parameter is NULL.
LINEERR_INVALPRIVSELECT	An invalid flag or combination of flags was set for the dwPrivileges parameter.
LINEERR_INVALRATE	The specified rate is invalid.
LINEERR_INVALREQUESTMODE	The LINEREQUESTMODE indicator is invalid.
LINEERR_INVALTERMINALID	The specified terminal identifier is invalid.
LINEERR_INVALTERMINALMODE	The specified terminal modes parameter is invalid.
LINEERR_INVALTIMEOUT	Timeouts are not supported or a value falls outside the valid range specified in LINEDEVCAPS.
LINEERR_INVALTONE	The specified custom tone does not represent a valid tone or is made up of too many frequencies or the specified tone structure does not describe a valid tone.
LINEERR_INVALTONELIST	The specified tone list is invalid.
LINEERR_INVALTONEMODE	The specified tone mode parameter is invalid.
LINEERR_INVALTRANSFERMODE	The specified transfer mode parameter is invalid.
LINEERR_LINEMAPPERFAILED	LINEMAPPER was the value passed in the dwDeviceID parameter, but no lines were found that match the requirements specified in the CallParams parameter.
LINEERR_NOCONFERENCE	The specified call is not a conference call handle or a participant call.
LINEERR_NODEVICE	The specified device identifier, which was previously valid, is no longer accepted because the associated device has been removed from the system since TAPI was last initialized. Alternately, the line device has no associated device for the given device class.
LINEERR_NODRIVER	Either tapiaddr.dll could not be located or the telephone service provider for the specified device found that one of its components is missing or corrupt in a way that was not detected at initialization time. The user should be advised to use the Telephony Control Panel to correct the problem.
LINEERR_NOMEM	Insufficient memory to perform the operation, or unable to lock memory.
LINEERR_NOMULTIPLEINSTANCE	A telephony service provider that does not support multiple instances is listed more than once in the [Providers] section in the registry. The application should advise the user to use the Telephony Control Panel to remove the duplicated driver.
LINEERR_NOMULTIPLEINSTANCE	Multiple instances of this service provider are not allowed.
LINEERR_NOREQUEST	There currently is no request pending of the indicated mode, or the application is no longer the highest-priority application for the specified request mode.
LINEERR_NOTOWNER	The application does not have owner privilege to the specified call.
LINEERR_NOTREGISTERED	The application is not registered as a request recipient for the indicated request mode.
LINEERR_OPERATIONFAILED	The operation failed for an unspecified or unknown reason.
LINEERR_OPERATIONUNAVAIL	The operation is not available, such as for the given device or specified line.
LINEERR_RATEUNAVAIL	The service provider currently does not have enough bandwidth available for the specified rate.
LINEERR_REINIT	If TAPI reinitialization has been requested, for example as a result of adding or removing a telephony service provider, then lineInitialize, lineInitializeEx, or lineOpen requests are rejected with this error until the last application shuts down its usage of the API (using lineShutdown), at which time the new configuration becomes effective and applications are once again permitted to call lineInitialize or lineInitializeEx.
LINEERR_REINIT	The application attempted to initialize TAPI twice.
LINEERR_REQUESTOVERRUN	More requests are pending than the device can handle.
LINEERR_RESOURCEUNAVAIL	Insufficient resources to complete the operation. For example, a line cannot be opened due to a dynamic resource overcommitment.
LINEERR_STRUCTURETOOSMALL	The dwTotalSize member of a structure does not specify enough memory to contain the fixed portion of the specified structure.
LINEERR_TARGETNOTFOUND	A target for the call handoff was not found. This can occur if the named application did not open the same line with the LINECALLPRIVILEGE_OWNER bit in the dwPrivileges parameter of lineOpen. Or, in the case of media-mode handoff, no application has opened the same line with the LINECALLPRIVILEGE_OWNER bit in the dwPrivileges parameter of lineOpen and with the media type specified in the dwMediaMode parameter having been specified in the dwMediaModes parameter of lineOpen.
LINEERR_TARGETSELF	The application invoking this operation is the target of the indirect handoff. That is, TAPI has determined that the calling application is also the highest priority application for the given media type.
LINEERR_UNINITIALIZED	The operation was invoked before any application called lineInitialize or lineInitializeEx.
LINEERR_USERCANCELLED	The user cancelled the call. This value is exposed only to applications that negotiate a TAPI version of 2.2 or higher.
LINEERR_USERUSERINFOTOOBIG	The string containing user-user information exceeds the maximum number of bytes specified in the dwUUIAcceptSize, dwUUIAnswerSize, dwUUIDropSize, dwUUIMakeCallSize, or dwUUISendUserUserInfoSize member of LINEDEVCAPS, or the string containing user-user information is too long.

Message (String)

The Message member holds a text with the description of the occured error. This text can be used to displayed user information and is read from the TAPI system files.