我們可以對集合中的字符串類型的數(shù)據(jù)排序。

            List<string> ary = new List<string>();
            ary.Add("a");
            ary.Add("你好");
            ary.Add("c");
            ary.Sort();
            foreach (string str in ary)
            {
                Console.WriteLine(str);
            }

但我們不能對兩個(gè)對象進(jìn)行排序。如

 List<Student> student = new List<Student>();
            Student stu1 = new Student("dd", 19);
            Student stu2 = new Student("你好", 13);
            Student stu3 = new Student("你", 13);
            student.Add(stu1);
            student.Add(stu2);
            student.Add(stu3);
            student.Sort();
            foreach(Student stu in student){
                Console.WriteLine(stu.Name+stu.Age);
            }
這樣程序會拋出異常，必須至少有一個(gè)對象實(shí)現(xiàn)IComparable

這個(gè)IComparable是一個(gè)接口里面有個(gè)一個(gè)沒有實(shí)現(xiàn)的方法

int CompareTo(Object obj)

如果實(shí)現(xiàn)此方法，就可以比較兩個(gè)對象了。

1年齡比較

 public int CompareTo(Student other)
        {
            //if (!(other is Student)) {
            //    throw new Exception("student");
            //}
            return this.Age.CompareTo(other.Age);
        }

2如果不是泛型，需要判斷兩個(gè)對象是否能夠比較和轉(zhuǎn)換對象

 public int CompareTo(object obj)
        {

//判斷類型
            if (!(obj is Teacher))
            {
                throw new Exception("不能比較");
            }
            else {

//轉(zhuǎn)換類型
                Teacher s = obj as Teacher;
                return this.YearOfwork.CompareTo(s.YearOfwork);
            }
        }

Sort()方法是集合中默認(rèn)的排序方法，它的排序方式可以通過IComparable接口實(shí)現(xiàn)。

如果要指定排序方式可以實(shí)現(xiàn)IComparer接口的Compare(T x,T y)方法Sort(Icomparer)

降序，升序年齡比較器

 class AgeDesc : IComparer<Student> {

        #region IComparer<Student> 成員

        public int Compare(Student x, Student y)
        {
            return y.Age.CompareTo(x.Age);
        }

        #endregion
    }
    class AgeAsc : IComparer<Student> {

        #region IComparer<Student> 成員

        public int Compare(Student x, Student y)
        {
            return x.Age.CompareTo(y.Age);
        }

        #endregion
    }

 private void btnAgeDesc_Click(object sender, EventArgs e)
        {
            student.Sort(new AgeDesc());
            Print(student);
        }
        private void Print(List<Student> stu) {
            this.listView1.Items.Clear();
            foreach (Student st in stu) {
                ListViewItem lvi = new ListViewItem(st.Name);
                lvi.SubItems.AddRange(new string[] {st.Age.ToString()});
                listView1.Items.Add(lvi);

            }
        }

        private void btnAgeAsc_Click(object sender, EventArgs e)
        {
            student.Sort(new AgeAsc());
            Print(student);
        }