title: I am having trouble with class System.String Represents text as a series of unicode characters. C#
body: <p>I am trying to get a Database to work and I am having trouble with my code.</p>
  
  <p>My code is:</p>
  
  <pre><code>namespace Books.Entities
  {
   public class Book
    {
       public int Id { get; set; }
  
       [Required]
       [**StringLength**(255)]
       public string Title { get; set; }
  
       public Genere Category { get; set; }
     } 
  }
  </code></pre>
  
  <p>The strength length gives me an error of 'Books.Entities.StringLengthAttribute' does not contain a constructor that takes 1 arguments.</p>