从.Net集合中获取密钥

I am using a StringDictionary to store key value pairs. I need to use the keys and values interchangeably i.e. I should be able to get the key from the value as in my case the values will be distinct.

我使用StringDictionary来存储键值对。我需要交替使用键和值,即我应该能够从值中获取键,因为在我的情况下,值将是不同的。

Is there a direct way I could do it (without looping)? Or if there is any other collection I could use to achieve this?

有没有直接的方法可以做到(没有循环)?或者,如果有任何其他收藏我可以用来实现这一目标?

Currently I am looping:

目前我正在循环:

public String GetKeyFromValue(string value)
        {
            foreach (KeyValuePair<string, string> kvp in instance)
            { 
                if (String.Equals(kvp.Value, value))
                    return kvp.Key;
            }

            throw new Exception ("Key not found in FilterControlMapping");
        }

Any help is much appreciated. Thanks.

任何帮助深表感谢。谢谢。

4 个解决方案

#1

You basically need to use two dictionaries encapsulated into one.

你基本上需要使用两个字典封装成一个。

There are already implementations here and here in other Stack Overflow questions.

这里和其他Stack Overflow问题已经有了实现。

#2

The only way I can think of is two dictionaries.

我能想到的唯一方法是两本词典。

D1 < Key, Value > D2 < Value, Key >

D1 D2 ,key> ,value>

You would be repeating your data though. But you could search both keys and values this way.

你会重复你的数据。但是你可以用这种方式搜索键和值。

#3

The best idea is to use Dictionary instead of StringDictionary as its obselete.. you can find out more about this here: StringDictionary vs Dictionary<string, string> regarding retrival you should go with linq internally it is using loops but still its much cleaner way..

最好的想法是使用Dictionary而不是StringDictionary作为它的obselete ..你可以在这里找到更多相关信息:StringDictionary vs Dictionary 关于retrival,你应该在内部使用linq它使用循环但仍然更清洁的方式.. ,string>

#4

This would also be possible using Dictionary:

这也可以使用Dictionary:

Dictionary<string, string> sd = new Dictionary<string, string>();
string sKey = sd.Single(kvp => kvp.Value.Equals("A value")).Key;

Note that the Single method will throw if the value occurs more than once. You could use First or even FirstOrDefault.

请注意,如果值多次出现,则抛出Single方法。您可以使用First或甚至FirstOrDefault。

Edit: As Jon Skeet commented this is still looping. The links he posted to a linked dictionary provide the solution.

编辑:正如Jon Skeet评论的那样,这仍然是循环的。他发布到链接词典的链接提供了解决方案。

#1