WIAS_TRACE macro (wiamdef.h)

Article
02/22/2024

The WIAS_TRACE macro writes a diagnostic message to the Wiatrace.log file.

Syntax

void WIAS_TRACE(
   x
);

Parameters

x

HInst - Handle to the DLL (driver).
format_string, ... - Specifies a variable argument list, which starts with an ANSI format string that describes the message and any format identifiers. The ellipsis (...) specifies a variable number of arguments that need to be output. The error text should be prefixed with the full name of the method or function and generate the message in the format of "class::method, error-text".

Return value

None

Remarks

To enable tracing in free builds, drivers must define the WIA_DEBUG macro by adding #define WIA_DEBUG before including any of the WIA headers. Tracing is enabled by default in checked and debug builds of the operating system.

The following is an example of how the macro would be used:

WIAS_TRACE((g_hInst,"WIA storage path = %ws",m_wszStoragePath));

This code snippet was taken from Wiadriver.cpp, which is included with the Windows Image Acquisition (WIA) driver samples on GitHub.

Requirements

Requirement	Value
Target Platform	Desktop
Header	wiamdef.h (include Wiautil.h)