Question

"InvalidOperationException was unhandled" in C# code

Asked by: Tony_k

The query below is firing an exception "InvalidOperationException was unhandled", can anyone help me to write an exception handler in C# for the method mentioned below. This exception is fired only when some of the data are null. like (_destVtCode == 0 )

private_GetTrCodePrvTime()
            {
                DataContext db = new DataContext();
                return db.LookupPts.Where(c => string.Compare(c.From_tCode, _DestVtCode) <= 0 && string.Compare(c.To_tCode, _DestVtCode) >= 0).OrderBy(c => c.TrCode).First();
            }

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Asked On: 2009-10-23 at 06:27:20ID24837855
Tags: InvalidOperationException was unhandled
Topics: CodeForge
,; C# Programming Language
,; Language Integrated Query - LINQ
Participating Experts: 2
Points: 500
Comments: 3

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Answers

by: djjariesPosted on 2009-10-23 at 07:08:11ID: 25644571

private_GetTrCodePrvTime()
{
  DataContext db = new DataContext();
  try {
    return db.LookupPts.Where(c => string.Compare(c.From_tCode, _DestVtCode) <= 0 && string.Compare(c.To_tCode, _DestVtCode) >= 0).OrderBy(c => c.TrCode).First();
  } catch (InvalidOperationException ex) {
    // Do your errorhandling here
    // MessageBox.Show("Error detected:\n" + ex.Message);
  }
}

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by: mikeadaPosted on 2009-10-23 at 15:16:20ID: 25649218

is _DestVtCode a string or an int? Int's can't be null so that's why I'm asking, it's a little confusing in your question.

If it's a string, then everywhere in your linq query that you have _DestVtCode, replace it with:
_DestVtCode && ""

that way if _DestVTCode is null it will use "" instead

by: Tony_kPosted on 2009-10-23 at 16:56:41ID: 31644999

It helps a lot thanks!

20120131-EE-VQP-002

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"InvalidOperationException was unhandled" in C# code

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