Using enumerations?

[cjard]

When working with datatables we can indicate we want changed and added rows with:

Dim chg as DataTable = realDatatable.GetChanges(Added+Modified)


Added and Modified are integer constants in the DataRowState enum..
The code above doesnt work with Option Strict on because added+modified is an integer type result not a datarowstate type result

Currently I just cast this integer result back into a datarowstate, but i cant help feeling that its just a bit messy and awkward.. If DRS is already an integer, why does the compiler take exception to me supplying it?

 

[cjard]

Ahhh... Thanks to all in here for some great info. The FlagsAttribute Class documentation noted by JohnH gives a great example of what Flags is used for/how it is treated as a cosmetic convenience. The article is:
http://msdn2.microsoft.com/en-us/library/system.flagsattribute.aspx

And in summary of the article, when you declare an enum as flags and give a set of constants that are powers of 2, then later you ToString a value in the enum, if it is the combination of more than one falg value, then the tostring representation gives all the values, separated by commas

If you had a Flags enum with Black=1 and White=2, and you said:
(Black Or White).ToString()
you would get a string "Black, White"

If the enum was not a Flags enum, then you would simply get "3"