Here’s a slightly easier way to work with flag enumerations.

Consider this simple enumeration:

/// <summary>
/// Options enumeration used to specify behaviour when calling MakeHandledServiceCall()
/// </summary>

[Flags]
public enum CallOptions
{
    /// <summary>
    /// No special handling
    /// </summary>
    None = 0,

    /// <summary>
    /// Display validation messages to the user automatically
    /// </summary>
    ShowValidation = 1,

    /// <summary>
    /// Display exception messages to the user automatically
    /// </summary>
    ShowExceptions = 2
}

Normally, to check if a particular option has been supplied, you need to write a clumsy test:

if ((options & CallOptions.ShowValidation) == CallOptions.ShowValidation)
{
    // Something
}

Historically, this is what we’ve been stuck with - even in C# 2.0, because you can’t constrain a generic method to work with enumerations.

However, with Extension methods in C# 3.0, we can write a helper like this:

/// <summary>
/// Test to see if the specified value includes a requested option
/// </summary>
/// <param name="aValue">Value to test</param>
/// <param name="aOption">Option to test for</param>
/// <returns>True of Value includes Option; false otherwise.</returns>
public static bool Includes(this CallOptions aValue, CallOptions aOption)
{
    return (aValue & aOption) == aOption;
}

Which makes the test much easier to read:

if (options.Includes(CallOptions.ShowValidation))
{
    // Something
}

Hope you find this useful!

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