RASDIALFUNC callback function (ras.h)

Article
04/02/2021

The RasDialFunc callback function is called by the RasDial function when a change of state occurs during a RAS connection process.

Syntax

RASDIALFUNC Rasdialfunc;

void Rasdialfunc(
  UINT unnamedParam1,
  tagRASCONNSTATE unnamedParam2,
  DWORD unnamedParam3
)
{...}

Parameters

unnamedParam1

unnamedParam2

unnamedParam3

Return value

None

Remarks

A RasDial connection operation is suspended during a call to a RasDialFunc callback function. For that reason, the RasDialFunc implementation should generally return as quickly as possible. There are two exceptions to that rule. Asynchronous (slow) devices such as modems often have time-out periods measured in seconds rather than milliseconds; a slow return from a RasDialFunc function is generally not a problem. The prompt return requirement also does not apply when dwError is nonzero, indicating that an error has occurred. It is safe, for example, to put up an error dialog box and wait for user input.

The RasDialFunc implementation should not depend on the order or occurrence of particular RASCONNSTATE connection states, because this may vary between platforms.

Do not call the RasDial function from within a RasDialFunc callback function. Call the RasGetConnectStatus, RasEnumEntries, RasEnumConnections, RasGetErrorString, and RasHangUp functions from within the callback function. For example, calling RasGetConnectStatus from within a callback function would be useful to determine the name and type of the connecting device.

Note For convenience, RasHangUp can be called from within a RasDialFunc callback function. However, much of the hang-up processing occurs after the RasDialFunc callback function has returned.

Note RasDialFunc is a placeholder for the application-defined or library-defined function name.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	ras.h