这是我自己编的一个小例子，大家评析一下！
include "mapbasic.def"
declare sub main
declare sub toolhandler
sub main
note "请选择mapinfo中的某一工具，然后在地图中单击" + "便可以在消息框中显示该处的坐标位置"
end sub
sub toolhandler
onerror goto error_trap
if windowinfo(frontwindow(),win_info_type)=win_mapper then
print "x:"+str$(commandinfo(cmd_info_x))
print "y:"+str$(commandinfo(cmd_info_y))
end if
done:
exit sub
error_trap:
note error$()
resume done
end sub