InternetQueryDataAvailable

Important:
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This function queries the amount of data available.

BOOL WINAPI InternetQueryDataAvailable(
HINTERNET
hFile
,  
LPDWORD
lpdwNumberOfBytesAvailable
,
DWORD
dwFlags
,
DWORD
dwContext
);

Parameters

hFile

Valid Internet file handle, as returned by InternetOpenUrl, FtpOpenFile, or HttpOpenRequest.

lpdwNumberOfBytesAvailable

Optional. Long pointer to a variable that receives the number of available bytes.

dwFlags

Reserved; set to zero.

dwContext

Reserved; set to zero.

Return Values

TRUE indicates success. FALSE indicates failure. To get extended error information, call GetLastError. If the function finds no matching files, GetLastErrorreturns ERROR_NO_MORE_FILES.

Windows CE Remarks

Windows CE stipulates that the hFileparameter must be a valid Internet file handle returned by the FtpOpenFile, FtpFindFirstFile, or HttpOpenRequestfunction.

The InternetQueryDataAvailablefunction can be completed in either synchronous or asynchronous mode.

Remarks

This function returns the number of bytes of data that are available to be read immediately by a subsequent call to InternetReadFile. If there is currently no data available and the end of the file has not been reached, the request waits until data becomes available. The amount of data remaining will not be recalculated until all available data indicated by the call to InternetQueryDataAvailableis read.

For HINTERNETHandles created by HttpOpenRequestand sent by HttpSendRequestEx, a call to HttpEndRequestmust be made on the handle before InternetQueryDataAvailablecan be used.

Requirements

Runs on	Versions	Defined in	Include	Link to
Windows CE OS	2.0 and later	Wininet.h		Wininet.lib

Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.