phoneOpen
The phoneOpen
function opens the specified phone device. A phone device can be opened using
either owner privilege or monitor privilege. An application that opens the
phone with owner privilege can control the phone's lamps, display, ringer, and
hookswitch or hookswitches. An application that opens the phone device with
monitor privilege is notified only about events that occur at the phone, such
as hookswitch changes or button presses. Ownership of a phone device is
exclusive. In other words, only one application can have a phone device opened
with owner privilege at a time. The phone device can, however, be opened
multiple times with monitor privilege.
LONG phoneOpen(
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HPHONEAPP hPhoneApp, |
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DWORD dwDeviceID, |
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LPHPHONE lphPhone, |
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DWORD dwAPIVersion, |
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DWORD dwExtVersion, |
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DWORD dwCallbackInstance, |
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DWORD dwPrivilege |
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); |
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Parameters
hPhoneApp
A handle to
the application's registration with TAPI.
dwDeviceID
The phone
device to be opened.
lphPhone
A pointer to
an HPHONE handle, which identifies the open phone device. Use this handle to
identify the device when invoking other phone control functions.
dwAPIVersion
The API
version number under which the application and Telephony API have agreed to
operate. This number is obtained from phoneNegotiateAPIVersion.
dwExtVersion
The extension
version number under which the application and the service provider agree to
operate. This number is zero if the application does not use any extensions.
This number is obtained from phoneNegotiateExtVersion.
dwCallbackInstance
User instance
data passed back to the application with each message. This parameter is not
interpreted by the Telephony API.
dwPrivilege
The privilege
requested. The dwPrivilege parameter can have only one bit set. This
parameter uses the following PHONEPRIVILEGE_ constants:
PHONEPRIVILEGE_MONITOR
An application
that opens a phone device with this privilege is informed about events and
state changes occurring on the phone. The application cannot invoke any
operations on the phone device that would change its state.
PHONEPRIVILEGE_OWNER
An application
that opens a phone device in this mode is allowed to change the state of the
lamps, ringer, display, and hookswitch devices of the phone. Having owner
privilege to a phone device automatically includes monitor privilege as well.
Return Values
Returns zero
if the request is successful or a negative error number if an error has
occurred. Possible return values are:
PHONEERR_ALLOCATED,
PHONEERR_NODRIVER, PHONEERR_BADDEVICEID, PHONEERR_NOMEM,
PHONEERR_INCOMPATIBLEAPIVERSION, PHONEERR_OPERATIONFAILED, PHONEERR_INCOMPATIBLEEXTVERSION,
PHONEERR_OPERATIONUNAVAIL, PHONEERR_INVALAPPHANDLE, PHONEERR_RESOURCEUNAVAIL,
PHONEERR_INVALPOINTER, PHONEERR_UNINITIALIZED, PHONEERR_INVALPRIVILEGE,
PHONEERR_REINIT, PHONEERR_INUSE, PHONEERR_NODEVICE, PHONEERR_INIFILECORRUPT.
Remarks
When opening
a phone device with monitor privileges, the application is sent messages when
events occur that change the status of the phone. Messages sent to the
application include PHONE_BUTTON
and PHONE_STATE.
The latter provides an indication of the phone's status item that has changed.
When opening
a phone with owner privilege, the phone device can be manipulated in ways that
affect the state of the phone device. An application should only open a phone
using owner privilege if it actively wants to manipulate the phone device, and
it should close the phone device when done to allow other applications to
control the phone.
When an
application opens a phone device, it must specify the negotiated API version
and, if it wants to use the phone's extensions, the phone's device-specific
extension version. This version number should have been obtained with the
function phoneNegotiateAPIVersion and phoneNegotiateExtVersion.
Version numbering allows the mix and match of different application versions
with different API versions and service-provider versions.
See Also