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Windows Embedded CE 6.0 R3


This function places a call on the specified line to the specified destination address. Optionally, call parameters can be specified if anything but default call setup parameters are requested.


LONG lineMakeCall(
  HLINE hLine, 
  LPHCALL lphCall, 
  LPCWSTR lpszDestAddress, 
  DWORD dwCountryCode, 
  LPLINECALLPARAMS const lpCallParams


  • hLine
    [in] Handle to the open line device on which a call is to be originated.
  • lphCall
    [in] Pointer to an HCALL handle. The handle is only valid after the LINE_REPLY message is received by the application indicating that the lineMakeCall function successfully completed. Use this handle to identify the call when invoking other telephony operations on the call. The application is initially the sole owner of this call. This handle is void if the function returns an error (synchronously or asynchronously by the reply message).
  • lpszDestAddress
    [in] Pointer to the null-terminated string that contains the destination address. This follows the standard dialable number format. This pointer can be NULL for non-dialed addresses (as with a hot phone). Service providers that have inverse multiplexing capabilities can enable an application to specify multiple addresses at once.
  • dwCountryCode
    [in] Specifies the country/region code of the called party. If a value of 0 is specified, a default is used by the implementation.
  • lpCallParams
    [in] Pointer to a LINECALLPARAMS structure. This structure enables the application to specify how it wants the call to be set up. If NULL is specified, a default 3.1-kHz voice call is established and an arbitrary origination address on the line is selected. This structure enables the application to select elements such as the call's bearer mode, data rate, expected media mode, origination address, blocking of caller identification data, and dialing parameters.

Return Value

A positive request identifier indicates that the function is completed asynchronously. A negative error number indicates that an error has occurred. The dwParam2 parameter of the corresponding LINE_REPLY message is zero if the function succeeds, or it is a negative error number if an error occurs. The following table shows the return values for this function.

Value Description


The address is blocked


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.


The call is unavailable.


The dialable address parameter contains dialing control characters that are not processed by the service provider.


The dialable address parameter contains dialing control characters that are not processed by the service provider.


The dialable address parameter contains dialing control characters that are not processed by the service provider.


The dialable address parameter contains dialing control characters that are not processed by the service provider.


The line is in use.


The address is invalid.


The address id is invalid.


The address mode is invalid.


The bearer mode is invalid.


Invalid parameters used for this call.


The country/region code provided was invalid.


The line handle is invalid.


The line is not in a state such that this operation can be performed.


The media mode is invalid.


The parameters are invalid.


The pointer is invalid.


The rate is invalid.


The operation requires more memory than is currently available.


The operation failed.


The operation is unavailable. With code division multiple access (CDMA), this function will fail if a call is currently in progress.

CDMA does not provide the necessary functionality to support the following TAPI functions:

Some cellular carriers provide equivalent functionality through the flash feature, which with TAPI 2.2 can be accessed with the lineGenerateDigits function. Because the exact flash sequences are controlled by the cellular providers, the application must be completely aware of the necessary codes implemented by the cellular providers.


The rate is unavailable.


The resource is unavailable.


The structure is too small.


The parameter is uninitialized.


The users information is too large.


If LINEERR_INVALLINESTATE is returned, the line is currently not in a state in which this operation can be performed. A list of currently valid operations can be found in the dwLineFeatures member (of the type LINEFEATURE_) in the LINEDEVSTATUS structure. If LINEERR_DIALBILLING, LINEERR_DIALQUIET, LINEERR_DIALDIALTONE, or LINEERR_DIALPROMPT is returned, none of the actions otherwise performed by lineMakeCall have occurred; for example, none of the dialable address prior to the offending character has been dialed, no hook switch state has changed, and so on.

After dialing has completed, several LINE_CALLSTATE messages are usually sent to the application to notify it about the progress of the call. No generally valid sequence of call-state transitions is specified, as no single fixed sequence of transitions can be guaranteed in practice. A typical sequence can cause a call to transition from dialtone, dialing, proceeding, ringback, to connected. With non-dialed lines, the call can typically transition directly to connected state.

An application has the option to specify an originating address on the specified line device. A service provider that models all stations on a switch as addresses on a single line device enables the application to originate calls from any of these stations using lineMakeCall.

The call parameters enable the application to make non-voice calls or request special call setup options that are not available by default.

An application can partially dial using lineMakeCall and continue dialing using the lineDial function. To abandon a call attempt, use the lineDrop function.

After lineMakeCall returns a success reply message to the application, a LINE_CALLSTATE message is sent to the application to indicate the current state of the call. This state is not necessarily LINECALLSTATE_DIALTONE.


Header tapi.h
Library coredll.lib
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also