dev_error_var — Define or undefine an error variable.
dev_error_var defines an error variable, i.e., a variable which
contains the result state of the last operator call.
ErrorVar will be 2 (H_MSG_TRUE) if no error had occurred.
The parameter Mode specifies whether the error variable should be
used (1) or not (0).
If an error variable is active it will be updated each time an operator
execution is finished. Thus a value is only valid until the next
call of an operator. The value can be saved by assigning it to
another variable (see example)
or by calling dev_error_var(ErrorVar,0).
ErrorVar (input_control) integer → (integer)
Name of the variable which shall contain the error status.
Default value: 'ErrorVar'
Mode (input_control) integer → (integer)
Switch the error variable on or off.
Default value: 1
List of values: 0, 1
dev_close_window ()
dev_open_window (0, 0, 512, 512, 'black', WindowHandle)
dev_error_var (Error, 1)
dev_set_check ('~give_error')
FileName := 'wrong_name'
read_image (Image, FileName)
ReadError := Error
if (ReadError != H_MSG_TRUE)
write_string (WindowHandle, 'wrong file name: '+FileName)
endif
If the values of the specified parameters are correct,
dev_error_var returns 2 (H_MSG_TRUE). Otherwise an
exception is raised and an error code returned.
dev_set_check,
if,
elseif,
else,
assign
Foundation