C#: Using Reflection to get constant values

It is generally good design practice to put constants in a static class to centralise messages and by using constants we can find typo’s at compile time instead of using string literals everywhere.

A common naming standard is also used which helps with auto-complete in Visual Studio, and will help us here by filtering constants if required.

An example constants class may be:

public class Constants
{
  public const string VALIDATION_CONCURRENCY = "This project was been modified by another user, please reload and try again.";
  public const string VALIDATION_REQUIRED = "The field {0} is empty and must be completed.";

  public const string EMAIL_MESSAGE_STD = "Dear {0}, blahblah";
}

Now we may be required to compile a list of validation messages for, say, spell and grammatical review. We could copy and paste and remove the C# parts using regular expressions, this is one way. Another way is to use reflection to find all validation constants in the Constants class. Here is the code:

            List<string> messages = new List<string>();
            foreach (FieldInfo field in typeof(Constants).GetFields().Where(f => f.Name.StartsWith("VALIDATION_")))
            {
                    messages.Add(field.GetRawConstantValue().ToString());
            }