1.sealed 不能派生
2.internal 仅仅在本项目中被访问
3.public 整个系统
4.private 本类访问
5.protected 本类、派生类访问
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ClassLibrary1 { public class Class3 { private int _age; protected string Name; public string Tel; } internal class Class33 { private int _age; protected string Name; public string Tel; } sealed class Class333 { private int _age; protected string Name; public string Tel; } abstract class Class3333 { private int _age; protected string Name; public string Tel; } static class Class33333 { private int _age; protected string Name; public string Tel; } }