WIAS_ASSERT macro (wiamdef.h)

Article
04/19/2022

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

Syntax

void WIAS_ASSERT(
   x,
   y
);

Parameters

x

Specifies any logical expression.

y

Handle to the DLL (driver).

Return value

None

Remarks

The WIAS_ASSERT macro is used to debug WIA drivers. It is used to test that a certain condition is met. If the Expression parameter evaluates to TRUE, this macro does nothing. If Expression evaluates to FALSE, the macro prints an error string to the Wiatrace.log diagnostic log file. This error message will contain the name and path to the calling driver and the line number in the driver source code where the WIAS_ASSERT macro failed.

The WIAS_ASSERT macro is available in Windows Vista and later versions of the operating system. This macro is the recommended way to implement WIA assertions on Windows Vista. WIAS_ASSERT allows error messages to be written to the log file (Wiatrace.log). The Wiatrace.log file is only available in Windows Vista, and later versions of the operating system. The utility used to view the contents of this log file is WiaTrcVw.exe.

To enable asserts in free builds, drivers must define the WIA_DEBUG macro by adding #define WIA_DEBUG to the driver's source code; this must be done before including any of the WIA headers. Asserts are enabled by default in checked and debug builds of the operating system.

Requirements

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