LINE_CLOSE (TAPI)

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

This 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 The line device handle or any call handles for calls on the line are no longer valid once this message has been sent.

Syntax

LINE_CLOSE 
    dwDevice = (DWORD) hLine;
    dwCallbackInstance = (DWORD) hCallback; 
    dwParam1 = (DWORD) 0;
    dwParam2 = (DWORD) 0; 
    dwParam3 = (DWORD) 0;

Parameters

• dwDevice
  Handle to the line device that was closed. This handle is no longer valid.

• dwCallbackInstance
  Callback instance supplied when opening the line.

• dwParam1
  Not used by this message. Value is NULL.

• dwParam2
  Not used by this message. Value is NULL.

• dwParam3
  Not used by this message. Value is NULL.

Return Value

None.

Remarks

The LINE_CLOSE message is only sent to any application after an open line has been forcibly closed. This can be done to prevent a single application from monopolizing a line device for too long. Whether or not the line can be reopened immediately after a forced close is device-specific.

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 the changes 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