XML配置文件的读取与修改

XML配置文件的读取与修改

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings>
<!--串口数据-->
<add key ="Port" value ="5"/>
</appSettings>
<!--数据库配置-->
<connectionStrings>
<add name="SMSSQL" connectionString="Data Source=192.168.0.8;Initial Catalog=SMS;User ID=sa;Password=sa" providerName="System.Data.SqlClient"/>
</connectionStrings>
</configuration>

 
一 . 读取配置文件
1. 用ConfigurationManager来读取
   引用：System.Configuration;
   public static string conString = ConfigurationManager.ConnectionStrings["SMSSQL"].ConnectionString;
 
2. 用XML中的XmlDocument
    引用：System.Xml;
    /// <summary>

        /// 读取数据库配置文件

        /// </summary>

        /// <returns>无返回值</returns>

        public static string readConn()

        {

            try

            {
                private static string configPath = System.Windows.Forms.Application.StartupPath + "\\App.config";

                System.IO.FileInfo FileInfo = new System.IO.FileInfo(configPath);

                //App.config文件是否存在

                if (!FileInfo.Exists)

                {

                    throw new ApplicationException("没有找到web.config配置文件！");

                }

                System.Xml.XmlDocument xmlDocument = new System.Xml.XmlDocument();

                xmlDocument.Load(configPath);

                string strConn = "";

                foreach (System.Xml.XmlNode Node in xmlDocument["configuration"]["connectionStrings"])

                {

                    if (Node.Name == "add")

                    {

                        if (Node.Attributes.GetNamedItem("name").Value == "SMSSQL")

                        {

                            strConn = Node.Attributes["connectionString"].Value;

                        }

                    }

                }

                return strConn;

            }

            catch (Exception ex)

            {

                

                throw new ApplicationException(ex.Message);

            }
 
二.  修改配置文件内
      private bool UpdateWebConfig()

        {

            string configPath = System.Windows.Forms.Application.StartupPath + "\\App.config";

            System.IO.FileInfo FileInfo = new System.IO.FileInfo(configPath);

            if (!FileInfo.Exists) //不存在web.config文件

            {

                throw new ApplicationException("没有找到web.config配置文件！");

            }

            System.Xml.XmlDocument xmlDocument = new System.Xml.XmlDocument();

            xmlDocument.Load(FileInfo.FullName);

            bool FoundIt = false;

            foreach (System.Xml.XmlNode Node in xmlDocument["configuration"]["connectionStrings"])

            {

                if (Node.Name == "add")

                {

                    if (Node.Attributes.GetNamedItem("name").Value == "OASQL")

                    {

                        Node.Attributes.GetNamedItem("connectionString").Value = String.Format("Data Source={0};database={1};User ID={2};Password={3};Packet Size=4096;Pooling=true;Max Pool Size=100;Min Pool Size=1", _DataSource, _DBName, _UserID, _PassWord);

                        FoundIt = true;

                        break;

                    }

                }

            }

            if (!FoundIt)

            {

                throw new ApplicationException("修改web.config配置文件失败！");

            }

            xmlDocument.Save(FileInfo.FullName);

            return FoundIt;