C#操作json数据时，对一个特定键的值进行修改

若strJson为字符串，值为{“ID”:"1","Code":"22","QuoteTime":"2013-12-12","Last":"22"}；

Code也为字符串，值为88

strJson = Regex.Replace(strJson,"(?<=\"Code\":\")[^\",]*",Code);

之后，strJson值为{“ID”:"1","Code":"88","Last":"22"}