IStreamAsync::ReadAsync method (shobjidl.h)
Reads information from a stream asynchronously. For example, the Shell implements this interface on file items when transferring them asynchronously.
Syntax
HRESULT ReadAsync(
[out] void *pv,
[in] DWORD cb,
[out, optional] LPDWORD pcbRead,
[in] LPOVERLAPPED lpOverlapped
);
Parameters
[out] pv
Type: void*
When this method returns successfully, returns a buffer that is cb bytes long and contains pcbRead bytes of information from the read operation.
[in] cb
Type: DWORD
The number of bytes to read from the stream.
[out, optional] pcbRead
Type: LPDWORD
Pointer to a DWORD value that, when this method returns successfully, states the actual number of bytes read to the buffer pointed to by pv. This value can be NULL.
[in] lpOverlapped
Type: LPOVERLAPPED
A pointer to an OVERLAPPED structure that contains information used in the asynchronous read operation.
Return value
Type: HRESULT
If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
Remarks
IStreamAsync::ReadAsync should reset the event specified by the hEvent member of the OVERLAPPED structure to a nonsignaled state when it begins the input/output (I/O) operation.
This method has been implemented in the Shell as a thin wrapper around the public ReadFile API.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows Vista [desktop apps only] |
Minimum supported server | Windows Server 2008 [desktop apps only] |
Target Platform | Windows |
Header | shobjidl.h |
Σχόλια
https://aka.ms/ContentUserFeedback.
Σύντομα διαθέσιμα: Καθ' όλη τη διάρκεια του 2024 θα καταργήσουμε σταδιακά τα ζητήματα GitHub ως μηχανισμό ανάδρασης για το περιεχόμενο και θα το αντικαταστήσουμε με ένα νέο σύστημα ανάδρασης. Για περισσότερες πληροφορίες, ανατρέξτε στο θέμα:Υποβολή και προβολή σχολίων για