Question

I’m trying to implement a Add Method for Dictionary<TKey,TValue> which takes a Propert as Parameter.

How I want to initiate the Dictionary:

ExpressionDictionary<string,string> OrigionalValues = new ExpressionDictionary<string,string>();

And I want to Add an item in a Property in code like:

public string Title
{
     get { return _title; }
     set
     {
          if (_title != value)
          {
               _title = value;
               OrigionalValues.Add(() => Title,value);                         
          }
     }
}

My ExpressionDictionary Class:

 public class ExpressionDictionary<T,TValue> : Dictionary<string, TValue>
 {
      public void Add(Expression<Func<T>> property, TValue value)
      {
           var body = property.Body as MemberExpression;
           if (body != null) Add(body.Member.Name, value);
      }
 }

So the PropertName is stored as the TKey of the Dictionary as a string. This works when the Property is type of string, but when I try to add a DateTime property and a string Property it hangs up, because it cannot convert, which is clear.

What I’m trying to achive is that I don’t need to hardcode the string Name of the Property like

OrigionalValues.Add("Title",value);

How can I design my Add Method or the ExpressionDictionary Class that I can call the Add Method from every Property type I want and the Property Name is stored as TKey? Is this even possible?

Answer 1

What about instantiating your dictionary like this?

var OrigionalValues = new ExpressionDictionary<object,object>();