DTWAIN_EnablePeekMessageLoop

Top  Previous  Next

The DTWAIN_EnablePeekMessageLoop function specifies whether DTWAIN will use the Windows API PeekMessage or GetMessage function when the Source is acquiring images.

 

DTWAIN_BOOL DTWAIN_EnablePeekMessageLoop (

DTWAIN_SOURCE

Source

DTWAIN_BOOL

bEnable );

 

Parameters

Source

An open TWAIN Source.

 

bEnable

Determines whether to turn on or off the detection of using the PeekMessage method of the acquisition loop.

 

Return Values

TRUE if successful, FALSE otherwise.  If the function returns FALSE, call DTWAIN_GetLastError() to get extended information.

 

Comments

The DTWAIN_EnablePeekMessageLoop function determines whether PeekMessage or GetMessage will be used as the looping method when the Source is acquiring images.  


The loop method is an internal process within DTWAIN when a Source is acquiring images, or when the Source's user-interface is being shown.  Almost all TWAIN drivers will work correctly using PeekMessage as the looping method, however there may be some edge-case Sources that do not work unless GetMessage is used.


By default, the looping method will always be determined by DTWAIN, with a majority of the time resulting in PeekMessage being used.  To force using a GetMessage loop, bEnable must be FALSE.