获取Json数据某节点的值

public static string GetJsonValue(string jsonStr, string key)
        {
            string result = string.Empty;
            if (!string.IsNullOrEmpty(jsonStr))
            {
                key = "\"" + key.Trim('"') + "\"";
                int index = jsonStr.IndexOf(key) + key.Length + 1;
                if (index > key.Length + 1)
                {
                    //先截逗号，若是最后一个，截“｝”号，取最小值
                    int end = jsonStr.IndexOf(',', index);
                    if (end == -1)
                    {
                        end = jsonStr.IndexOf('}', index);
                    }

                    result = jsonStr.Substring(index, end - index);
                    result = result.Trim(new char[] { '"', ' ', '\'' }); //过滤引号或空格
                }
            }
            return result;
        }

 --上面的不规范，参考下面写法

  public static String GetJsonValue(String jsonStr, String key){
        String result ="";
        if (!jsonStr.equals("")){
            key = "\"" + key.trim() + "\"";
            int index = jsonStr.indexOf(key) + key.length() + 1;
            if (index > key.length() + 1){
                //先截逗号，若是最后一个，截“｝”号，取最小值
                int end = jsonStr.indexOf(',', index);
                if (end == -1){
                    end = jsonStr.indexOf('}', index);
                }

                result = jsonStr.substring(index, end - index);
                result = result.trim(); //过滤引号或空格
            }
        }
        return result;
    }

public static string GetXMLstrByKey(string Key, XmlDocument xml)
        {
            object strValue = xml.SelectSingleNode("xml").SelectSingleNode(Key).InnerText;
            if (strValue != null)
            {
                return strValue.ToString();
            }
            else
            {
                return "";
            }
        }