[导入]继承示例

 先介绍一个包含继承所有要素的例子：

InheritExample
using ...System;

namespace Donis.CSharpBook
...{
    public class Starter
    ...{
        Main()#region Main()
        public static void Main()
        ...{

            XParent parent = new XParent();
            parent.MethodA();
            XChild child = new XChild();
            child.MethodA();
            child.MethodB();
            child.FieldA = 10;
            Console.WriteLine(child.FieldA);
            Console.ReadKey();
        }
        #endregion

        XParent#region XParent
        public class XParent
        ...{
            public void MethodA()          //一个方法。
            ...{
                Console.WriteLine("XParent.MethodA called from ...{0}.",
                    this.GetType().ToString());
            }

            private int propFieldA;          //一个字段。

            public int FieldA                   //一个属性
            ...{
                get
                ...{
                    return propFieldA;
                }
                set
                ...{
                    propFieldA = value;
                }
            }

        }
        #endregion

        XChild : XParnt#region XChild : XParnt
        public class XChild : XParent
        ...{
            public int MethodB()         //添加了一个方法。
            ...{
                Console.WriteLine("XChild.MethodB called from ...{0}.",
                    this.GetType().ToString());
                return fieldb;
            }

            private int fieldb = 5;            //添加了一个字段。
        }
        #endregion
    }
}

这个例子输出的结果是：

第一行是   parent.MethodA(); 输出的。
第二行是 child.MethodA();输出的。说明继承了，XParent中的方法。
第三行是 child.MethodB();输出的。XChild通过向集合添加一个方法来扩展XParent。
child.FieldA = 10;继承了属性。

下面是一个完整的列表，包括System.Object类中被重写的方法：

Employee
using ...System;
using System.Collections;
//System.Collections 命名空间包含接口和类，这些接口和类定义各种对象（如列表、队列、位数组、哈希表和字典）的集合。  

namespace sliuqin.CS
...{
    public class Staerter
    ...{
        public static void Main()
        ...{
            Employee obj1 = new Employee(5678);
            Employee obj2 = new Employee(5678);
            if (obj1 == obj2)
            ...{
                Console.WriteLine("equals");
            }
            else
            ...{
                Console.WriteLine("not equals");
            }
            Console.ReadKey();
        }

    }
    Employee类#region Employee类
    class Employee
    ...{
        public Employee(int id)
        ...{
            if ((id < 1000) || (id > 9999))
            ...{
                throw new Exception("INvalid Employee ID");
            }
            propID = id;
        }
        public static bool operator ==(Employee obj1, Employee obj2)
        ...{
            return obj1.Equals(obj2);
        }
        public static bool operator !=(Employee obj1, Employee obj2)
        ...{
            return !obj1.Equals(obj2);
        }


        属性#region 属性
        First#region First
        private string propFirst;
        public string First
        ...{
            get
            ...{
                return propFirst;
            }
            set
            ...{
                propFirst = value;
            }
        }
                #endregion

        Last#region Last
        private string propLast;
        public string Last
        ...{
            get
            ...{
                return propLast;
            }
            set
            ...{
                propLast = value;
            }
        }
        #endregion

        EmplID#region EmplID
        private readonly int propID;
        public int EmplID
        ...{
            get
            ...{
                return propID;
            }
        }
        #endregion

        FullName#region FullName
        public string FullName
        ...{
            get
            ...{
                return propFirst + " " + propLast;
            }
        }
        #endregion  
        #endregion

        重写 Equals () GetHashCode() 和 ToString()#region 重写 Equals () GetHashCode() 和 ToString()
        public override bool Equals(object obj)
        ...{
            Employee _obj = obj as Employee;
            if (obj == null)
            ...{
                return false;
            }
            return this.GetHashCode() == _obj.GetHashCode();
        }
        public override int GetHashCode()
        ...{
            return EmplID;
        }

        public override string ToString()
        ...{
            return FullName;
        }  
        #endregion
    }  
    #endregion
}

文章来源:http://www.link-to.cn/post/2007/10/InheritExample.aspx