OrderByDescending不是在LINQ的正常工作 [英] OrderByDescending not working properly in Linq

问题描述

我使用LINQ和在C＃下面的代码：

I am using Linq and have the following code in C#:

leaves = GetAnnualLeaves();
otherleaves = GetOtherLeaves();
leaves.AddRange(otherleaves);
leaves.OrderByDescending(e => e.StartDate);

基本上我想显示年度和其他假期的名单，我想按降序排列显示它们。问题是，它总是显示其他叶在年节末不管。所以基本上它显示是这样的：

Basically I am trying to display list of annual and other leaves and I want to display them in DESCENDING order. Problem is it always shows "Other Leaves" at the end of "Annual Leaves" no matter what. So basically it displays like this:

2013-06-29 Annual
2012-01-01 Annual
2011-05-02 Annual
2013-05-01 Other

在实际上它应该显示是这样的：

When in fact it should display like this:

2013-06-29 Annual
2013-05-01 Other
2012-01-01 Annual
2011-05-02 Annual

任何想法，为什么由降序排列不工作？

Any idea why order by descending is not working?

修改

我收到的时候我用铸造错误CONCAT。

I am getting casting error when I use CONCAT.

这两个年和其他叶子是同类型的，但是当我做

Both "Annual" and "Other" leaves are of same type but when I do

leaves = leaves.Concat(otherleaves) 

然后该项目不编译并给出错误

then the project doesn't compile and gives error

Cannot implicitly convert type System.Collections.Generic.IEnumerable<MyEntity> to System.Collections.Generic.List<MyEntity>

如果我去做类型转换：

And if I do type cast:

leaves = (List<MyEntity>)leaves.Concat(otherleaves)

然后我得到运行时错误。

then I get runtime error.

推荐答案

您不分配结果 OrderByDescending

leaves = leaves.OrderByDescending(e => e.StartDate).ToList();

还是

or do

leaves = leaves.Concat(otherleaves).OrderByDescending(e => e.StartDate).ToList();

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