using System;
 
class Untitled
{
    class Class1
    {
        public int DuplicateProperty {get;set;}
    }
 
    class Class2 : Class1
    {
        public new int DuplicateProperty{get;set;} // 有覆盖的要用 new
        public int ItemId {get;set;}
    }
    static void Main(string[] args)
    {
        Console.WriteLine("Hello World");
        Class2 c = new Class2();
        c.DuplicateProperty = 1;
        Class1 a = new Class1();
        Console.WriteLine(a.DuplicateProperty.ToString());  //值为0
        Console.WriteLine(c.DuplicateProperty.ToString());  //值为1 
    }
}

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