如何以相反的顺序迭代。net IList集合?

I have an IList that contains items ( parent first ), they need to be added to a Diagram Document in the reverse order so that the parent is added last, drawn on top so that it is the first thing to be selected by the user.

我有一个IList，它包含项目(父类优先)，它们需要以相反的顺序添加到关系图文档中，以便最后添加父类，绘制在顶部，以便用户首先选择它。

What's the best way to do it? Something better/more elegant than what I am doing currently which I post below..

最好的方法是什么?比我现在正在做的事情更好/更优雅。

4 个解决方案

#1

If you have .NET 3.5 you could use LINQ's Reverse?

如果你有。net 3.5，你可以使用LINQ的反向?

foreach(var item in obEvtArgs.NewItems.Reverse())
{
   ...
}

(Assuming you're talking about the generic IList)

(假设你说的是一般的伊利亚特)

#2

Based on the comments to Davy's answer, and Gishu's original answer, you could cast your weakly-typed System.Collections.IList to a generic collection using the System.Linq.Enumerable.Cast extension method:

根据对戴维答案的评论，以及Gishu最初的答案，您可以使用弱类型的System.Collections。使用System.Linq.Enumerable. enumerable . enumerable进行泛型集合。把扩展方法:

var reversedCollection = obEvtArgs.NewItems
  .Cast<IMySpecificObject>( )
  .Reverse( );

This removes the noise of both the reverse for loop, and the as cast to get a strongly-typed object from the original collection.

这将消除反向for循环和从原始集合中获取强类型对象的as转换的噪声。

#3

NewItems is my List here... This is a bit clunky though.

newitem是我的列表……这有点笨拙。

for(int iLooper = obEvtArgs.NewItems.Count-1; iLooper >= 0; iLooper--)
            {
                GoViewBoy.Document.Add(CreateNodeFor(obEvtArgs.NewItems[iLooper] as IMySpecificObject, obNextPos));
            }

#4

You don't need LINQ:

你不需要LINQ:

var reversed = new List<T>(original); // assuming original has type IList<T>
reversed.Reverse();
foreach (T e in reversed) {
  ...
}

#1