Trapping a Null Object


I have a DataRow object I'm using where the first field is a ColumnObject.  I test to make sure the ColumnObject is not null as follows:

                if (dataRow[ColumnObject] == null)
                    fieldString.Append("".PadRight(ColumnWidth, ' '));
                    return fieldString.ToString();

What's happening is that I get an error in my catch block telling me that "ColumnObject" can't be null.  But that's exactly what I'm testing for.  What am I missing?
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Guy Hengel [angelIII / a3]Billing EngineerCommented:
check against DBNull.Value instead of null

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NigelRocksAuthor Commented:
IsNull is only not avaible for a column value, but is available for a DataRow.
NigelRocksAuthor Commented:
Actually, I thought this was working but apparently not.  The problem is here:

                if (dataRow[ColumnObject] == DBNull.Value)

The column object is evaluated before it is even compared to DBNull.Value, as far as I can see.  In other words, the run-time bombs because it see ColumnObject as an invalid value.  Ideas?
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