基础 - get、set - 字段读写权限

属性未封装，可读可写

public class person
    {
      public string name;
    }

public class person
    {
      public string Name{set;get;}
    }

属性已封装，可读可写

private string name;//私有
public string Name
    {
      get { return name; }
      set { name = value; }
    }