This function closes the specified open line device.
At a Glance
| Header file: | Tapi.h |
| Windows CE versions: | 1.0 and later |
Syntax
LONG lineClose(HLINE hLine);
Parameters
hLine
[in] Handle to the open line device to be closed. After the line has been successfully closed, this handle is no longer valid.
Return Values
Zero indicates success. A negative error number indicates that an error occurred. Possible error values are as follows:
Remarks
If an application calls lineClose while it still has active calls on the opened line, the application's ownership of these calls is revoked. If the application owns these calls, the calls are dropped as well. It is good programming practice for an application to dispose of the calls it owns on an open line by explicitly relinquishing ownership and/or by dropping these calls prior to closing the line.
If the line was closed successfully, a LINE_LINEDEVSTATE message is sent to all applications monitoring the line status for open/close changes. Outstanding asynchronous replies are suppressed.
Service providers may find it useful or necessary to forcibly reclaim line devices from an application that has the line open. This can be useful to prevent an application from monopolizing the line device. If this happens, a LINE_CLOSE message is sent to the application, specifying the line handle of the line device that was closed.
The lineOpen function allocates resources to the invoking application, and applications can be prevented from opening a line if resources are unavailable. Therefore, an application that only occasionally uses a line device, such as for making outgoing calls, should close the line to free resources and enable other applications to open the line.
See Also