WebSocketBeginClientHandshake function (websocket.h)

The WebSocketBeginClientHandshake function begins the client-side handshake.

Syntax

HRESULT WebSocketBeginClientHandshake(
  [in]           WEB_SOCKET_HANDLE             hWebSocket,
  [in, optional] PCSTR                         *pszSubprotocols,
  [in]           ULONG                         ulSubprotocolCount,
  [in, optional] PCSTR                         *pszExtensions,
  [in]           ULONG                         ulExtensionCount,
  [in, optional] const PWEB_SOCKET_HTTP_HEADER pInitialHeaders,
  [in]           ULONG                         ulInitialHeaderCount,
  [out]          PWEB_SOCKET_HTTP_HEADER       *pAdditionalHeaders,
  [out]          ULONG                         *pulAdditionalHeaderCount
);

Parameters

[in] hWebSocket

Type: WEB_SOCKET_HANDLE

WebSocket session handle returned by a previous call to WebSocketCreateClientHandle.

[in, optional] pszSubprotocols

Type: PCSTR*

Pointer to an array of sub-protocols chosen by the application. Once the client-server handshake is complete, the application must use the sub-protocol returned by WebSocketEndClientHandshake. Must contain one subprotocol per entry.

[in] ulSubprotocolCount

Type: ULONG

Number of sub-protocols in pszSubprotocols.

[in, optional] pszExtensions

Type: PCSTR*

Pointer to an array of extensions chosen by the application. Once the client-server handshake is complete, the application must use the extension returned by WebSocketEndClientHandshake. Must contain one extension per entry.

[in] ulExtensionCount

Type: ULONG

Number of extensions in pszExtensions.

[in, optional] pInitialHeaders

Type: const PWEB_SOCKET_HTTP_HEADER

Pointer to an array of WEB_SOCKET_HTTP_HEADER structures that contain the request headers to be sent by the application. The array must include the Host HTTP header as defined in RFC 2616.

[in] ulInitialHeaderCount

Type: ULONG

Number of request headers in pInitialHeaders.

[out] pAdditionalHeaders

Type: PWEB_SOCKET_HTTP_HEADER

On successful output, pointer to an array of WEB_SOCKET_HTTP_HEADER structures that contain the request headers to be sent by the application. If any of these headers were specified in pInitialHeaders, the header must be replaced.

[out] pulAdditionalHeaderCount

Type: ULONG*

On successful output, number of response headers in pAdditionalHeaders.

Return value

Type: HRESULT

If the function succeeds, it returns S_OK.

If the function fails, it returns a system error code defined in WinError.h.

Remarks

To complete the client-side handshake, applications must call WebSocketEndClientHandshake. Once the client-server handshake is complete, the application may use the session functions.

Requirements

See also

WEB_SOCKET_HTTP_HEADER

WebSocketBeginServerHandshake

WebSocketEndClientHandshake

WebSocketEndServerHandshake