http://www.soaspx.com/dotnet/csharp/csharp_20130513_10318.html
Distinct()方法在MSDN中的示例
public class Product
{
public string Name { get; set; }
public int Code { get; set; }
}
首先，应用HASH有以下几点优点
• Key lookup occurs in memory, avoiding costly disk access.
• When a key lookup occurs, only a small subset of the records are searched.
• The key and dat
