城杆

  /// <summary>
        /// 设置app.config中的某个key的value.
        /// </summary>
        /// <param name="AppKey">key</param>
        /// <param name="AppValue">value</param>
        public void SetValue(string AppKey, string AppValue)
        {
            XmlDocument xDoc = new XmlDocument();

            //此处配置文件在程序目录下
            xDoc.Load(Application.StartupPath + "\\PoCollect.exe.config");
            XmlNode xNode;
            XmlElement xElem1;
            XmlElement xElem2;
            xNode = xDoc.SelectSingleNode("//appSettings");
            xElem1 = (XmlElement)xNode.SelectSingleNode("//add[@key='" + AppKey + "']");
            if (xElem1 != null)
            {
                xElem1.SetAttribute("value", AppValue);
            }
            else
            {
                xElem2 = xDoc.CreateElement("add");
                xElem2.SetAttribute("key", AppKey);
                xElem2.SetAttribute("value", AppValue);
                xNode.AppendChild(xElem2);
            }
            xDoc.Save(Application.StartupPath + "\\PoCollect.exe.config");
        }