C# List 排序各種用法與比較

下麵介紹各種List的sort的用法與比較

首先，我們建一個People的實體，有name、age、sex的屬性，我們要排序的欄位是年齡age

新建一個實體類

    public class People
    {
        public string name { get; set; }
        public int age { get; set; }
        public string sex { get; set; }
    }

新建list的數據

            List<People> peoples = new List<People>()
            {
                new People() {age = 11, name="alun", sex = "男"},
                new People() {age=25, name = "陳敬桃", sex = "男"},
                new People() {age=9, name = "惠安", sex = "男"},
                new People() {age = 45, name = "小票", sex = "女"},
                new People() {age=3, name = "曉鷗", sex = "女"},
                new People() {age=70, name = "望謨", sex = "男"}
            };

1. 第1種排序方法，使用 IComparer

    public class PeopleAgeComparer : IComparer<People>
    {
        public int Compare(People p1, People p2)
        {
            return p1.age.CompareTo(p2.age);
        }
    }

peoples.Sort(new PeopleAgeComparer());

可以看到第一種方法比價麻煩，要新建一個新的類來做

2. 第2種排序方法，使用委托來排序

peoples.Sort(delegate (People p1, People p2) { return p1.age.CompareTo(p2.age); });

看委托的方式很方便，不用新建類這麼麻煩。

3. 第2種排序方法，使用Lambda表達式來排序

peoples.Sort( (a, b) => a.age.CompareTo(b.age) );

目測排序有這3種方法，個人覺得還是Lambda表達式使用得方便。