C# Linq的OrderByDescending()方法 – 根据指定的键按降序对序列的元素进行排序

当使用C#Linq时，我们常常需要在对数据进行排序时使用OrderByDescending()方法。这个方法可以根据指定的条件对数据进行降序排序。

下面是使用OrderByDescending()方法的完整攻略：

格式

var result = collection.OrderByDescending(item => item.Property);

其中，collection是一个IEnumerable类型的集合，item是集合中元素的一个别名，Property是item中被选中用于排序的属性。

示例1

假设我们有一个存储学生信息的Student类：

public class Student 
{
    public string Name { get; set; }
    public int Age { get; set; }
    public int Grade { get; set; }
}

现在我们有一个Student集合，需要按照学生的年龄进行降序排序：

List<Student> students = new List<Student>
{
    new Student { Name = "Tom", Age = 20, Grade = 85 },
    new Student { Name = "Jerry", Age = 19, Grade = 80 },
    new Student { Name = "Jim", Age = 21, Grade = 95 },
    new Student { Name = "Frank", Age = 18, Grade = 75 },
    new Student { Name = "Bob", Age = 22, Grade = 90 },
};

var sortedStudents = students.OrderByDescending(s => s.Age);

这样就按照Age的降序排列了。

示例2

现在我们有一个存储音乐信息的Music类：

public class Music
{
    public string Name { get; set; }
    public string Singer { get; set; }
    public int Views { get; set; }
}

现在我们有一个Music的集合，需要按照音乐视频播放量进行降序排序：

List<Music> musics = new List<Music>
{
    new Music { Name = "Better With You", Singer = "Austin Mahone", Views = 230000 },
    new Music { Name = "Can't Stop the Feeling", Singer = "Justin Timberlake", Views = 5600000 },
    new Music { Name = "Cheyenne", Singer = "Jason Derulo", Views = 23000000 },
    new Music { Name = "Cheap Thrills", Singer = "Sia", Views = 330000000 },
    new Music { Name = "Closer", Singer = "The Chainsmokers", Views = 11000000 },
};

var sortedMusics = musics.OrderByDescending(m => m.Views);

这样就按照Views的降序排列了。

以上就是使用C#Linq的OrderByDescending()方法的完整攻略。