C # Dictionary Gets the corresponding key value by value [forwarding]

1: The most straightforward loop traversal method, can be divided into the traversal Key--value key value pairs and all key two forms of expression

2: Query in Linq (of course, add the corresponding namespace using System.Linq)

Here's a very simple code example:

Private voidGetdickeybyvalue () {Dictionary<string,string> dic =Newdictionary<string,string>(); Dic. ADD ("1","1"); Dic. ADD ("2","2"); Dic. ADD ("3","2"); //foreach KeyValuePair traversing            foreach(keyvaluepair<string,string> kvpinchdic) {if(KVP. Value.equals ("2"))                {                     //... kvp. Key;                }            }            //foreach dic. Keys            foreach(stringKeyinchDiC. Keys) {if(Dic[key]. Equals ("2"))                {                     //... key                }            }            //Linq            varKeys = dic. Where (q = Q.value = ="2"). Select (q = q.key);//Get all keysList<string> keylist = ( fromQinchDiCwhereQ.value = ="2"                                    SelectQ.key). tolist<string> ();//Get all keys            varFirstkey = dic. FirstOrDefault (q = Q.value = ="2"). Key;//get first key}

Original address: http://www.cnblogs.com/mingmingruyuedlut/archive/2013/05/23/3067227.html

C # Dictionary Gets the corresponding key value by value [forwarding]