using System.Web; 

public string GetLeaderInfo(string symbol)
{
    //获取高管信息的路径         
    XElement ele = XElement.Load("path.xml");
    string path = ele.Element("leader").Value;

    //首次读取缓存
    string jsoncache = HttpRuntime.Cache.Get(symbol) as string;
    if (jsoncache == null || jsoncache.Equals(""))
    {
        //读取数据
        XmlDocument doc = new XmlDocument();
        doc.Load(path);

        string strSearch = "root/高管信息[@代码='" + symbol + "']";

        XmlNode searchNode = doc.SelectSingleNode(strSearch);
        XmlElement element = (XmlElement)searchNode;
        xmltoJson json = new xmltoJson();
        jsoncache = json.XmlToJSON(element);
        //加缓存
        HttpRuntime.Cache.Insert(symbol, jsoncache, null, DateTime.UtcNow.AddMinutes(2), System.Web.Caching.Cache.NoSlidingExpiration);
    }
    return jsoncache;
}