对appSettings节点进行新增、修改、删除、读取操作的类AppSettingsHelper

 

 

using  System;
using  System.Configuration;
using  System.Reflection;
using  System.Web;
using  System.Xml;

/*   编写日期: 2008.4.4
 *  更新日期: 
 *  编写人  :James.Chen
 *  修改历史及原因:
 * 
  */
namespace  AppFrameWork
{
     ///  

     ///  配置文件类型,是WinForm还是WebForm
     ///  

     public   enum  ConfigFileType
    {
        WebConfig,
        AppConfig
    }
     ///  

     ///  对AppSettings节点进行增加，删除，修改操作.
     ///  

     public   class  AppSettingsHelper
    {
         public   static   string  docName  =  String.Empty;
         private   static  XmlNode node  =   null ;


         ///  

         ///  设置节点的值，若该节点不存在，则创建一个新的节点。
         ///  

         ///  
         ///  
         ///  
         ///  
         public   static   bool  SetValue( string  key,  string  value, ConfigFileType cfgType)
        {
            XmlDocument cfgDoc  =   new  XmlDocument();
            loadConfigDoc(cfgDoc, cfgType);
             //  retrieve the appSettings node   
            node  =  cfgDoc.SelectSingleNode( " //appSettings " );
             if  (node  ==   null )
            {
                 throw   new  InvalidOperationException( " appSettings section not found " );
            }
             try
            {
                 //  XPath select setting "add" element that contains this key       
                XmlElement addElem  =  (XmlElement)node.SelectSingleNode( " //add[@key=' "   +  key  +   " '] " );
                 if  (addElem  !=   null )
                {
                    addElem.SetAttribute( " value " , value);
                }
                 //  not found, so we need to add the element, key and value   
                 else
                {
                    XmlElement entry  =  cfgDoc.CreateElement( " add " );
                    entry.SetAttribute( " key " , key);
                    entry.SetAttribute( " value " , value);
                    node.AppendChild(entry);
                }
                 // save it   
                saveConfigDoc(cfgDoc, docName);
                 return   true ;
            }
             catch
            {
                 return   false ;
            }
        }
         ///  

         ///  获取节点的值
         ///  

         ///  
         ///  
         ///  
         public   static   string  GetValue( string  key, ConfigFileType cfgType)
        {
            XmlDocument cfgDoc  =   new  XmlDocument();
            loadConfigDoc(cfgDoc, cfgType);
             //  retrieve the appSettings node   
            node  =  cfgDoc.SelectSingleNode( " //appSettings " );
             if  (node  ==   null )
            {
                 throw   new  InvalidOperationException( " appSettings section not found " );
            }
            
                 //  XPath select setting "add" element that contains this key       
                XmlElement addElem  =  (XmlElement)node.SelectSingleNode( " //add[@key=' "   +  key  +   " '] " );
                 if  (addElem  !=   null )
                {
                    
                     return  addElem.GetAttribute( " value " );
                }
                 //  not found, so we need to add the element, key and value   
                 else
                {
                     throw   new  ArgumentException( string .Format( " key '{0}' not found " , key));
                }

           
        }


         private   static   void  saveConfigDoc(XmlDocument cfgDoc,  string  cfgDocPath)
        {
             try
            {
                XmlTextWriter writer  =   new  XmlTextWriter(cfgDocPath,  null );
                writer.Formatting  =  Formatting.Indented;
                cfgDoc.WriteTo(writer);
                writer.Flush();
                writer.Close();
                 return ;
            }
             catch
            {
                 throw ;
            }
        }



         ///  

         ///  移除节点
         ///  

         ///  
         ///  
         ///  
         public   static   bool  RemoveElement( string  elementKey, ConfigFileType cfgType)
        {
             try
            {
                XmlDocument cfgDoc  =   new  XmlDocument();
                loadConfigDoc(cfgDoc, cfgType);
                 //  retrieve the appSettings node  
                node  =  cfgDoc.SelectSingleNode( " //appSettings " );
                 if  (node  ==   null )
                {
                     throw   new  InvalidOperationException( " appSettings section not found " );
                }
                 //  XPath select setting "add" element that contains this key to remove      
                node.RemoveChild(node.SelectSingleNode( " //add[@key=' "   +  elementKey  +   " '] " ));
                saveConfigDoc(cfgDoc, docName);
                 return   true ;
            }
             catch
            {
                 return   false ;
            }
        }


         ///  

         ///  修改节点的值
         ///  

         ///  
         ///  
         ///  
         public   static   bool  ModifyElement( string  elementKey, ConfigFileType cfgType)
        {
             try
            {
                XmlDocument cfgDoc  =   new  XmlDocument();
                loadConfigDoc(cfgDoc, cfgType);
                 //  retrieve the appSettings node  
                node  =  cfgDoc.SelectSingleNode( " //appSettings " );
                 if  (node  ==   null )
                {
                     throw   new  InvalidOperationException( " appSettings section not found " );
                }
                 //  XPath select setting "add" element that contains this key to remove      
                node.RemoveChild(node.SelectSingleNode( " //add[@key=' "   +  elementKey  +   " '] " ));
                saveConfigDoc(cfgDoc, docName);
                 return   true ;
            }
             catch
            {
                 return   false ;
            }
        }



         private   static  XmlDocument loadConfigDoc(XmlDocument cfgDoc, ConfigFileType cfgType)
        {
             //  load the config file   
             if  (cfgType  ==  ConfigFileType.AppConfig)
            {
                docName  =  ((Assembly.GetEntryAssembly()).GetName()).Name;
                docName  +=   " .exe.config " ;
            }
             else
            {
                docName  =  HttpContext.Current.Server.MapPath( " web.config " );
            }
            cfgDoc.Load(docName);
             return  cfgDoc;
        }

    }
}

App.config： 

xml version = " 1.0 "  encoding = " utf-8 "   ?>
< configuration >
   < appSettings >

    
       < add key = " maximized "  value = " False " />
      
   appSettings >
configuration >

 

读操作：

bool  maximized  =   false ;

             bool .TryParse(AppSettingsHelper.GetValue( " maximized " , ConfigFileType.AppConfig),  out  maximized);


             if  (maximized)
                 this .WindowState  =  FormWindowState.Maximized;

 

写操作：

if ( this .WindowState == FormWindowState.Maximized)
            AppSettingsHelper.SetValue( " maximized " , " True " , ConfigFileType.AppConfig);
             else
            AppSettingsHelper.SetValue( " maximized " ,  " False " , ConfigFileType.AppConfig);

其他操作略