IStiDeviceControl::WriteToErrorLog method (stiusd.h)

The IStiDeviceControl::WriteToErrorLog method allows a user-mode still image minidriver to write a message into the still image error log.

Syntax

HRESULT WriteToErrorLog(
  DWORD   dwMessageType,
  LPCWSTR pszMessage,
  DWORD   dwErrorCode
);

Parameters

dwMessageType

Caller-supplied constant value representing the message type. The following values are defined in Sti.h:

STI_TRACE_INFORMATION

STI_TRACE_WARNING

STI_TRACE_ERROR

pszMessage

Caller-supplied pointer to a message string to be written to the log file.

dwErrorCode

Not used.

Return value

If the operation succeeds, the method returns S_OK. Otherwise, it returns one of the STIERR-prefixed error codes defined in stierr.h.

Remarks

The still image error log file is named sti_trace.log and is located in the Windows directory. Control Panel allows a user to select which still image error types (informational, warning, or error) are written to the error log (see Nonmodifiable Registry Entries).

Error messages should be reserved for critical error conditions, such as device hardware failures. Informational messages can be used for your own debugging purposes. Logged messages aren't visible to users, but they might be used by a support engineer to help debug a user's problems.

A still image minidriver receives an IStiDeviceControl interface pointer as input to its IStiUSD::Initialize method.

Requirements

Requirement	Value
Target Platform	Desktop
Header	stiusd.h (include Stiusd.h)