标签：操作 语言 desc 通过 定义 反转 opera 指定 --
| Sorting Operator | Description |
|---|---|
| OrderBy | 通过给定的字段进行升序 降序 排序 |
| OrderByDescending | 通过给定字段进行降序排序，仅在方法查询中使用 |
| ThenBy | 第二级升序排序，仅在方法查询中使用 |
| ThenByDescending | 第二级降序排序，仅在方法查询中使用 |
| Reverse | 反转集合，仅在方法查询中使用 |
IList<Student> studentList = new List<Student>() { new Student() { StudentID = 1, StudentName = "John", Age = 18 } , new Student() { StudentID = 2, StudentName = "Steve", Age = 15 } , new Student() { StudentID = 3, StudentName = "Bill", Age = 25 } , new Student() { StudentID = 4, StudentName = "Ram" , Age = 20 } , new Student() { StudentID = 5, StudentName = "Ron" , Age = 19 } }; var orderByResult = from s in studentList orderby s.StudentName select s; var orderByDescendingResult = from s in studentList orderby s.StudentName descending select s;
OrderBy扩展方法有两个重载方法，第一个方法接受一个类型参数，你可以指定通过哪个字段进行排序
第二个方法接受一个实现IComparer的类型，用户可以自定义排序
public static IOrderedEnumerable<TSource> OrderBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector); public static IOrderedEnumerable<TSource> OrderBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector, IComparer<TKey> comparer);
IList<Student> studentList = new List<Student>() { new Student() { StudentID = 1, StudentName = "John", Age = 18 } , new Student() { StudentID = 2, StudentName = "Steve", Age = 15 } , new Student() { StudentID = 3, StudentName = "Bill", Age = 25 } , new Student() { StudentID = 4, StudentName = "Ram" , Age = 20 } , new Student() { StudentID = 5, StudentName = "Ron" , Age = 19 } }; var studentsInAscOrder = studentList.OrderBy(s => s.StudentName);
OrderByDescending
IList<Student> studentList = new List<Student>() { new Student() { StudentID = 1, StudentName = "John", Age = 18 } , new Student() { StudentID = 2, StudentName = "Steve", Age = 15 } , new Student() { StudentID = 3, StudentName = "Bill", Age = 25 } , new Student() { StudentID = 4, StudentName = "Ram" , Age = 20 } , new Student() { StudentID = 5, StudentName = "Ron" , Age = 19 } }; var studentsInDescOrder = studentList.OrderByDescending(s => s.StudentName);
多个排序
可以使用多个字段以逗号隔开进行排序，集合首先以第一个字段进行排序，如果第一个字段有相同的值，则根据第二个字段进行排序
注意：
LINQ包含五种排序操作:OrderBy、OrderByDescending、ThenBy、ThenByDescending、Reverse
查询语言不支持OrderByDescending、ThenBy、ThenByDescending、Reverse，它仅支持Order By从句后面跟ascending、descending
查询语法支持多字段排序，
LINQ 学习路程 -- 查询操作 OrderBy & OrderByDescending
标签：操作 语言 desc 通过 定义 反转 opera 指定 --
原文地址：http://www.cnblogs.com/lanpingwang/p/6602258.html
