LowLevelWriteStringNoPoll

Writes raw bytes directly to a device without going through the formatted I/O write buffer.

virtual HRESULT LowLevelWriteStringNoPoll(const CString& strBuf, long* pcchActual = NULL, bool bAddTrailing = true, long lTimeout = CUR_TIMEOUT)  override;	

virtual HRESULT LowLevelWriteStringNoPoll(BSTR strBuf, long* pcchActual = NULL, bool bAddTrailing = true, long lTimeout = CUR_TIMEOUT) override;

Parameters

strBuf: [int] Array of characters to be written to the device.
pcchActual: [out] Actual number of bytes written to the device. pcchActual may be set to NULL if the caller is not interested in knowing the actual number of bytes written.
bAddTrailing: [in] true to have the trailing characters specified by the SetTrailingForWrites function automatically added to strBuf before sending to the device.
lTimeout: [in] I/O timeout value in milliseconds.

Return Value

Returns S_OK if successful, otherwise a failure HRESULT.

Remarks

This function behaves identically to the LowLevelWriteString function except that the device is not polled for errors after the data is written.

Caution
It is critical that these low-level functions not be intermixed with buffered I/O functions in a sequence of operations, such as a set of calls implementing a single driver method. The buffered I/O functions assume that all data read from or sent to the device passes through the I/O buffer, and intermixing these calls with low-level functions that directly access the device can produce incorrect results and/or I/O errors.

Caution

It is critical that these low-level functions not be intermixed with buffered I/O functions in a sequence of operations, such as a set of calls implementing a single driver method. The buffered I/O functions assume that all data read from or sent to the device passes through the I/O buffer, and intermixing these calls with low-level functions that directly access the device can produce incorrect results and/or I/O errors.

Example

The following example demonstrates use of the LowLevelWriteStringNoPoll function.

C++

Copy

// CoAcme4321.cpp
STDMETHODIMP Acme4321::IAcme4321_Configure(BSTR bstrData)
{
  HRESULT hr = S_OK;

  hr = io.LowLevel.LowLevelWriteStringNoPoll(bstrData);

  return hr;
}

Other Resources

LowLevelWrite

LowLevelWriteNoPoll

LowLevelWriteString