查詢排序 - OrderBy() ThenBy() OrderByDescending() ThenByDescending()

string[] names= { "mark", "steve", "adam" };

上升：

查詢語法

var sortedNames =
    from name in names
    orderby name
    select name;

方法語法

var sortedNames = names.OrderBy(name => name);

sortedNames 按以下順序包含名稱：adam，mark，steve

降：

查詢語法

var sortedNames =
    from name in names
    orderby name descending
    select name;

方法語法

var sortedNames = names.OrderByDescending(name => name);

sortedNames 按以下順序包含名稱：steve，mark，adam

按幾個領域排序

Person[] people =
{
    new Person { FirstName = "Steve", LastName = "Collins", Age = 30},
    new Person { FirstName = "Phil" , LastName = "Collins", Age = 28},
    new Person { FirstName = "Adam" , LastName = "Ackerman", Age = 29},
    new Person { FirstName = "Adam" , LastName = "Ackerman", Age = 15}
};

查詢語法

var sortedPeople = from person in people
                   orderby person.LastName, person.FirstName, person.Age descending
                   select person;

方法語法

 sortedPeople = people.OrderBy(person => person.LastName)
                      .ThenBy(person => person.FirstName)
                      .ThenByDescending(person => person.Age);

結果

1. Adam Ackerman 29
2. Adam Ackerman 15
3. Phil Collins  28
4. Steve Collins 30