The lineConfigDialogEdit function causes the provider of the specified line device to display a dialog (attached to hwndOwner of the application) to allow the user to configure parameters related to the line device.

LONG lineConfigDialogEdit(

DWORD dwDeviceID,

HWND hwndOwner,

LPCSTR lpszDeviceClass,

LPVOID const lpDeviceConfigIn,

DWORD dwSize,

LPVARSTRING lpDeviceConfigOut




The line device to be configured.


A handle to a window to which the dialog is to be attached. Can be NULL to indicate that any window created during the function should have no owner window.


A pointer to a NULL-terminated string that identifies a device class name. This device class allows the application to select a specific subscreen of configuration information applicable to that device class. This parameter is optional and can be left NULL or empty, in which case the highest level configuration is selected.


A pointer to the opaque configuration data structure that was returned by lineGetDevConfig (or a previous invocation of lineConfigDialogEdit) in the variable portion of the VARSTRING structure.


The number of bytes in the structure pointed to by lpDeviceConfigIn. This value will have been returned in the dwStringSize field in the VARSTRING structure returned by lineGetDevConfig or a previous invocation of lineConfigDialogEdit.


A pointer to the memory location of type VARSTRING where the device configuration structure is returned. Upon successful completion of the request, this location is filled with the device configuration. The dwStringFormat field in the VARSTRING structure will be set to STRINGFORMAT_BINARY. Prior to calling lineGetDevConfig (or a future invocation of lineConfigDialogEdit), the application should set the dwTotalSize field of this structure to indicate the amount of memory available to TAPI for returning information.

Return Values

Returns zero if the request is successful or a negative error number if an error has occurred. Possible return values are:



If LINEERR_STRUCTURETOOSMALL is returned, the dwTotalSize field of the VARSTRING structure pointed to by lpDeviceConfigOut does not specify enough memory to contain the entire configuration structure. The dwNeededSize field has been set to the amount required. To the extent that user entries were reflected in information that could not be returned due to insufficient space, those edits are lost; applications should therefore allocate the maximum amount of space that may be needed by the device class to return its configuration structure (for more information, see documentation for the device class).

The lineConfigDialogEdit function causes the service provider to display a modal dialog (attached to hwndOwner of the application) to allow the user to configure parameters related to the line specified by dwDeviceID.

The lpszDeviceClass parameter allows the application to select a specific subscreen of configuration information applicable to the device class in which the user is interested; the permitted strings are the same as for lineGetID. For example, if the line supports the Comm API, passing "COMM" as lpszDeviceClass causes the provider to display the parameters related specifically to Comm (or, at least, start at the corresponding point in a multilevel configuration dialog chain, so the user doesn't have to "dig" to find the parameters of interest).

The lpszDeviceClass parameter would be "tapi/line" , "", or NULL to cause the provider to display the highest level configuration for the line.

The difference between this function and lineConfigDialog is the source of the parameters to edit and the result of the editing. In lineConfigDialog, the parameters edited are those currently in use on the device (or set for use on the next call), and any changes made have (to the maximum extent possible) an immediate impact on any active connection; also, the application must use lineGetDevConfig to fetch the result of parameter changes from lineConfigDialog. With lineConfigDialogEdit, the parameters to edit are passed in from the application, and the results are returned to the application, with no impact on active connections; the results of the editing are returned with this function, and the application does not need to call lineGetDevConfig. Thus, lineConfigDialogEdit permits an application to provide the ability for the user to set up parameters for future calls without having an impact on any active call. Note, however, the output of this function can be passed to lineSetDevConfig to affect the current call or next call.

Although this is a new function which older applications would not be expected to call, for backward compatibility, they should not be prevented from doing so; the function will work the same way for all applications.

See Also

, lineGetDevConfig, lineGetID, lineSetDevConfig, VARSTRING

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