How to set ExpandoObject's dictionary as case insensitive?

Question

given the code below

dynamic e = new ExpandoObject();
var d = e as IDictionary<string, object>;
for (int i = 0; i < rdr.FieldCount; i++)
   d.Add(rdr.GetName(i), DBNull.Value.Equals(rdr[i]) ? null : rdr[i]);

Is there a way to make it case insensitive so given the field name employee_name

e.Employee_name works just as well as e.employee_name

there doesn't seem to be an obvious way, perhaps a hack ?

Answer 1

I've been using this “Flexpando” class (for flexible expando) which is case-insensitive.

It's similar to Darin's MassiveExpando answer in that it gives you dictionary support, but by exposing this as a field it saves having to implement 15 or so members for IDictionary.

public class Flexpando : DynamicObject {
    public Dictionary<string, object> Dictionary
        = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);

    public override bool TrySetMember(SetMemberBinder binder, object value) {
        Dictionary[binder.Name] = value;
        return true;
    }

    public override bool TryGetMember(GetMemberBinder binder, out object result) {
        return Dictionary.TryGetValue(binder.Name, out result);
    }
}

Answer 2

You may checkout Massive's implementation of a MassiveExpando which is case insensitive dynamic object.

Answer 3

More as a curiosity than as a solution:

dynamic e = new ExpandoObject();
var value = 1;
var key = "Key";

var resul1 = RuntimeOps.ExpandoTrySetValue(
    e, 
    null, 
    -1, 
    value, 
    key, 
    true); // The last parameter is ignoreCase

object value2;
var result2 = RuntimeOps.ExpandoTryGetValue(
    e, 
    null, 
    -1, 
    key.ToLowerInvariant(), 
    true, 
    out value2);  // The last parameter is ignoreCase

RuntimeOps.ExpandoTryGetValue/ExpandoTrySetValue use internal methods of ExpandoObject that can control the case sensitivity. The null, -1, parameters are taken from the values used internally by ExpandoObject (RuntimeOps calls directly the internal methods of ExpandoObject)

Remember that those methods are This API supports the .NET Framework infrastructure and is not intended to be used directly from your code.

Answer 4

Another solution is to create a ExpandoObject-like class by deriving from System.Dynamic.DynamicObject and overriding TryGetValue and TrySetValue.

Answer 5

public static class IDictionaryExtensionMethods
{
  public static void AddCaseInsensitive(this IDictionary dictionary, string key, object value)
  {
    dictionary.Add(key.ToUpper(), value);
  }

  public static object Get(this IDictionary dictionary, string key)
  {
    return dictionary[key.ToUpper()];
  }
}