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!
Comments
blog comments powered by Disqus