While the expression within the redraw <boolean> context is being evaluated, screen redraws are completely disabled, and the modify and motion panels are suspended.
This is basically an exception safe form of
disableSceneRedraw(); < expr >; enableSceneRedraw()
That is, if an exception is thrown in < expr >, the scene redraws will be automatically re-enabled as part of the exception handling. The modify and motion panels are suspended if they are the currently active command panel. If the expression sets the current command panel to either modify or motion, the command panel will not be suspended at that point.
with redraw off
for t=0 to 10 do
exportFile ("outfile_"+(t as string)+".dxf") #noPrompt selectedOnly:true
disableSceneRedraw & enableSceneRedraw