What are some advanced usage patterns for enumerations in C#?

What are some advanced usage patterns for enumerations in C#?

In C#, enumerations (enums) can be used in various advanced ways, such as combining flags, using them with attributes, or even implementing interfaces. Would you like to explore a specific pattern?

Can you explain how to use enums with flags?

Certainly! You can use the [Flags] attribute to define an enum that can represent a combination of values. For example:

[Flags]
enum Permissions
{
    None = 0,
    Read = 1,
    Write = 2,
    Execute = 4,
    All = Read | Write | Execute
}

This allows you to combine permissions like this: Permissions.Read | Permissions.Write. Would you like to see an example of how to check these flags?

Yes, please show me how to check for specific flags.

You can check for specific flags using the bitwise AND operator. For example:

Permissions userPermissions = Permissions.Read | Permissions.Write;

if ((userPermissions & Permissions.Read) == Permissions.Read)
{
    Console.WriteLine("User has read permission.");
}

This checks if the Read permission is set. Would you like to know more about using enums with attributes?

Definitely! How can I use attributes with enums?

You can define custom attributes and apply them to enum members. For example:

public class DescriptionAttribute : Attribute
{
    public string Description { get; }
    public DescriptionAttribute(string description) => Description = description;
}

public enum Status
{
    [Description("Pending approval")]
    Pending,
    [Description("Approved")]
    Approved,
    [Description("Rejected")]
    Rejected
}

You can then retrieve these descriptions using reflection. Would you like to see how to do that?