RESUME Questions

[Lance Edmonds]

ON ERROR GOTO ErrTrap
...
ON ERROR GOTO 0
...
ON ERROR RESUME NEXT
...
ON ERROR GOTO ErrTrap

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

Lance, Thank you!!!

Could you be a little more specific about Q3.

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[Lance Edmonds]

All error traps must have a RESUME <linelabel>.

ie,

FUNCTION MyFunc....
   ON ERROR GOTO MyFuncTrap
   ....
    
MyFuncResumePoint:
   EXIT FUNCTION
 
MyFuncTrap:
   ' handle error here
   RESUME MyFuncResumePoint
END FUNCTION

You can't resume the same line again - it is not possible - the compiler would need to add significant additional code to your app for every single line of code.

Instead, you simply need to write your code to either handle errors as they occur (no trap or use RESUME NEXT, and check ERR as necessary) or write your error trap to branch back above the line you wish to resume again - you can have several RESUME <Linelabel> depending on the state of ERR, etc. This way permits you to keep the code size down and performance up, whilst constructing as much or a little error testing as you need yourself.


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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

I have a couple of questions in regard to error handling.

Q1 - The manual notes that you must terminate a error trap with a RESUME statement. Could you not just fall out of the sub/func as well or do you have to RESUME?

Q2 - I see noted a RESUME label and a RESUME Next but not a RESUME. How would you try the offending line again?

Q3 - If you want to cancel error trap for a couple lines of code you can use the RESUME NEXT. How do you start the error trap again for that sub/func?

Private Sub MySub()
  On Error Goto ErrorRoutine
  (some code....................)

  'stop error trap
  On Error Resume Next 
  (some code....................)
  On Error Goto 0

  (some code....................)

ErrorRoutine:
  (some code....................)

End Sub

In the code above after the On Error Goto 0 would the On Error Goto ErrorRoutine be in effect?

Thanks.