C＃中的列表排序

Question

我有对象列表，我需要根据对象的property1对列表进行排序，并且我需要再次对具有对象的property2的结果列表进行排序，而不会丢失在第一次排序中完成的分组..例如：obj具有2个属性名称和位置i需要具有已按区域排序的对象的最终列表，而相同区域的对象应按名称排序...

Answer 1

(Assuming you don't have LINQ available to you, which makes this trivial.)

If you look in MiscUtil , you'll find two useful classes: ProjectionComparer and LinkedComparer (IIRC).

ProjectionComparer basically implements the LINQ "order by" concept - you specify how to convert a source element to a key value, and the comparer will order by those key values.

LinkedComparer takes two comparers and returns a new comparer which uses the "primary" comparer first, and the "secondary" comparer if values are equal with respect to the primary one.

Create two projection comparers (one for each property) and then a linked comparer with the two of them, then pass that to List<T>.Sort . Let me know if you need a full code sample, but it would be something like (using C# 3):

var comparer = new LinkedComparer<Foo>
     (ProjectionComparer<Foo>.Create(x => x.FirstProperty),
      ProjectionComparer<Foo>.Create(x => x.SecondProperty));

(In C# 2 you could use anonymous methods, they'd just be a bit more long-winded.)

Answer 2

听起来您想使用LINQ的orderby和thenby语法。

Answer 3

A List has a Sort method which takes a Comparision delegate as an argument. There are also overloads where you can pass in your own comparer.

So, you can write a class which implements IComparer. Then, in the implementation of this class, you write the code where you compare the 2 objects on the properties you want.