public class PropertyComparer<T> : IEqualityComparer<T>
	{
		private PropertyInfo _PropertyInfo;

		/// <summary>
		/// Creates a new instance of PropertyComparer.
		/// </summary>
		/// <param name="propertyName">The name of the property on type T 
		/// to perform the comparison on.</param>
		public PropertyComparer(string propertyName)
		{
			//store a reference to the property info object for use during the comparison
			_PropertyInfo = typeof(T).GetProperty(propertyName,
		BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.Public);
			if (_PropertyInfo == null)
			{
				throw new ArgumentException(string.Format("{0} is not a property of type {1}.", propertyName, typeof(T)));
			}
		}

		#region IEqualityComparer<T> Members

		public bool Equals(T x, T y)
		{
			//get the current value of the comparison property of x and of y
			object xValue = _PropertyInfo.GetValue(x, null);
			object yValue = _PropertyInfo.GetValue(y, null);

			//if the xValue is null then we consider them equal if and only if yValue is null
			if (xValue == null)
				return yValue == null;

			//use the default comparer for whatever type the comparison property is.
			return xValue.Equals(yValue);
		}

		public int GetHashCode(T obj)
		{
			//get the value of the comparison property out of obj
			object propertyValue = _PropertyInfo.GetValue(obj, null);

			if (propertyValue == null)
				return 0;

			else
				return propertyValue.GetHashCode();
		}

		#endregion
	}

//Extension Class
public static class EnumerableExtender
{
	public static IEnumerable<TSource> Distinct<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
	{
		HashSet<TKey> seenKeys = new HashSet<TKey>();
		foreach (TSource element in source)
		{
			var elementValue = keySelector(element);
			if (seenKeys.Add(elementValue))
			{
				yield return element;
			}
		}
	}
}

//using 
distinctDatas = datas.Distinct(person => person.Name);