LINE_CLOSE message

The TAPI LINE_CLOSE message is sent when the specified line device has been forcibly closed. The line device handle or any call handles for calls on the line are no longer valid once this message has been sent.

Parameters

hDevice

A handle to the line device that was closed. This handle is no longer valid.

dwCallbackInstance

The callback instance supplied when opening the line.

dwParam1

Unused.

dwParam2

Unused.

dwParam3

Unused.

Return value

No return value.

Remarks

The LINE_CLOSE message is sent to any application only after the TAPI service provider (TSP) has forcibly closed an open line. Whether or not the line can be reopened immediately after a forced close is device-specific.

The causing condition can be a significant change of state, a hardware error, a loss of connection to a server, or even potentially to prevent a single application from monopolizing a line device for too long. A line device can also be forcibly closed after the user has modified the configuration of that line or its driver. If the user wants the configuration changes to be effective immediately (as opposed to after the next system restart), and they affect the application's current view of the device (such as a change in device capabilities), then a service provider can forcibly close the line device.

Requirements