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C# Dictionary通过value获取对应的key值

1:最直白的循环遍历方法,可以分为遍历key--value键值对以及所有的key两种表现形式

2:用Linq的方式去查询(当然了这里要添加对应的命名空间 using System.Linq)

 如下为一个十分简单的代码示例:

private void GetDicKeyByValue(){    Dictionary<string, string> dic = new Dictionary<string, string>();    dic.Add("1", "1");    dic.Add("2", "2");    dic.Add("3", "2");    //foreach KeyValuePair traversing    foreach (KeyValuePair<string, string> kvp in dic)    {        if (kvp.Value.Equals("2"))        {             //...... kvp.Key;        }    }    //foreach dic.Keys    foreach (string key in dic.Keys)    {        if (dic[key].Equals("2"))        {             //...... key        }    }    //Linq    var keys = dic.Where(q => q.Value =http://www.mamicode.com/= "2").Select(q => q.Key);  //get all keys    List<string> keyList = (from q in dic                            where q.Value =http://www.mamicode.com/= "2"                            select q.Key).ToList<string>(); //get all keys    var firstKey = dic.FirstOrDefault(q => q.Value =http://www.mamicode.com/= "2").Key;  //get first key}

 

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C# Dictionary通过value获取对应的key值