WFDOpenHandle function (wlanapi.h)

Article
10/13/2021

The WFDOpenHandle function opens a handle to the Wi-Fi Direct service and negotiates a version of the Wi-FI Direct API to use.

Syntax

DWORD WFDOpenHandle(
  [in]  DWORD   dwClientVersion,
  [out] PDWORD  pdwNegotiatedVersion,
  [out] PHANDLE phClientHandle
);

Parameters

[in] dwClientVersion

The highest version of the Wi-Fi Direct API the client supports.

For Windows 8 and Windows Server 2012, this parameter should be set to WFD_API_VERSION, constant defined in the Wlanapi.h header file.

[out] pdwNegotiatedVersion

A pointer to a DWORD to received the negotiated version.

If the WFDOpenHandle function is successful, the version negotiated with the Wi-Fi Direct Service to be used by this session is returned. This value is usually the highest version supported by both the client and Wi-Fi Direct service.

[out] phClientHandle

A pointer to a HANDLE to receive the handle to the Wi-Fi Direct service for this session.

If the WFDOpenHandle function is successful, a handle to the Wi-Fi Direct service to use in this session is returned.

Return value

If the function succeeds, the return value is ERROR_SUCCESS.

If the function fails, the return value may be one of the following return codes.

Return code	Description
ERROR_INVALID_PARAMETER	The parameter is incorrect. This error is returned if the pdwNegotiatedVersion parameter is NULL or the phClientHandle parameter is NULL. This value is also returned if the dwClientVersion parameter is not equal to WFD_API_VERSION.
ERROR_NOT_ENOUGH_MEMORY	Not enough storage is available to process this command. This error is returned if the system was unable to allocate memory to create the client context.
ERROR_REMOTE_SESSION_LIMIT_EXCEEDED	An attempt was made to establish a session to a network server, but there are already too many sessions established to that server. This error is returned if too many handles have been issued by the Wi-Fi Direct service.
RPC_STATUS	Various error codes.

Remarks

The WFDOpenHandle function is part of Wi-Fi Direct, a new feature in Windows 8 and Windows Server 2012. Wi-Fi Direct is based on the development of the Wi-Fi Peer-to-Peer Technical Specification v1.1 by the Wi-Fi Alliance (see Wi-Fi Alliance Published Specifications). The goal of the Wi-Fi Peer-to-Peer Technical Specification is to provide a solution for Wi-Fi device-to-device connectivity without the need for either a Wireless Access Point (wireless AP) to setup the connection or the use of the existing Wi-Fi adhoc (IBSS) mechanism.

In order to use Wi-Fi Direct, an application must first obtain a handle to the Wi-Fi Direct service by calling the WFDOpenHandle function. The Wi-Fi Direct (WFD) handle returned by the WFDOpenHandle function is used for subsequent calls made to the Wi-Fi Direct service. Once an application is done using the Wi-Fi Direct service, the application should call the WFDCloseHandle function to signal to the Wi-Fi Direct service that the application is done using the service. This allows the Wi-Fi Direct service to release resources used by the application.

Requirements

Requirement	Value
Minimum supported client	Windows 8 [desktop apps only]
Minimum supported server	Windows Server 2012 [desktop apps only]
Target Platform	Windows
Header	wlanapi.h
Library	Wlanapi.lib
DLL	Wlanapi.dll