1using System;
2using System.Configuration;
3using System.Reflection;
4using System.Web;
5using System.Xml;
6public enum ConfigFileType
7{
8    WebConfig,
9    AppConfig
10}
11
12namespace WebApplication1
13{
14    /**//// <summary>
 15    /// Summary description for ReadWriteConfig.
 16    /// </summary>
 17    public class ReadWriteConfig
18    {
19        public string docName = String.Empty;
20        private XmlNode node=null;
21        private int _configType;
22        public int ConfigType
23        {
24            get{ return _configType; }
25            set{ _configType=value; }
26        }
27
28        SetValue#region SetValue
29        public bool SetValue(string key, string value)
30        {
31            XmlDocument cfgDoc = new XmlDocument();
32            loadConfigDoc(cfgDoc);
33            // retrieve the appSettings node   
 34            node =  cfgDoc.SelectSingleNode("//appSettings");
35            if( node == null )
36            {
37                throw new InvalidOperationException( "appSettings section not found");
38            }
39            try
40            {
41                // XPath select setting "add" element that contains this key       
 42                XmlElement addElem= (XmlElement)node.SelectSingleNode("//add[@key='" +key +"']") ;
43                if(addElem!=null)
44                {
45                    addElem.SetAttribute("value",value);
46                }
47                // not found, so we need to add the element, key and value   
 48                else
49                {
50                    XmlElement entry = cfgDoc.CreateElement("add");
51                    entry.SetAttribute("key",key);
52                    entry.SetAttribute("value",value);
53                    node.AppendChild(entry);
54                }
55                //save it   
 56                saveConfigDoc(cfgDoc,docName);
57                return true;
58            }
59            catch
60            {
61                return false;
62            }
63        }
64
65        #endregion
66
67        saveConfigDoc#region saveConfigDoc
68        private void saveConfigDoc(XmlDocument cfgDoc,string cfgDocPath)
69        {
70            try
71            {
72                XmlTextWriter writer = new XmlTextWriter( cfgDocPath , null );
73                writer.Formatting = Formatting.Indented;
74                cfgDoc.WriteTo( writer );
75                writer.Flush();
76                writer.Close();
77                return;
78            }
79            catch
80            {
81                throw;
82            }
83        }
84
85        #endregion
86
87        removeElement#region removeElement
88        public bool removeElement (string elementKey)
89        {
90            try
91            {
92                XmlDocument cfgDoc = new XmlDocument();
93                loadConfigDoc(cfgDoc);
94                // retrieve the appSettings node  
 95                node =  cfgDoc.SelectSingleNode("//appSettings");
96                if( node == null )
97                {
98                    throw new InvalidOperationException( "appSettings section not found");
99                }
100                // XPath select setting "add" element that contains this key to remove      
101                node.RemoveChild( node.SelectSingleNode("//add[@key='" +elementKey +"']") );
102                saveConfigDoc(cfgDoc,docName);
103                return true;
104            }
105            catch
106            {
107                return false;
108            }
109        }
110        #endregion
111
112        modifyElement#region modifyElement
113        public bool modifyElement (string elementKey)
114        {
115            try
116            {
117                XmlDocument cfgDoc = new XmlDocument();
118                loadConfigDoc(cfgDoc);
119                // retrieve the appSettings node  
120                node =  cfgDoc.SelectSingleNode("//appSettings");
121                if( node == null )
122                {
123                    throw new InvalidOperationException( "appSettings section not found");
124                }
125                // XPath select setting "add" element that contains this key to remove      
126                node.RemoveChild(node.SelectSingleNode("//add[@key='" +elementKey +"']"));
127                saveConfigDoc(cfgDoc,docName);
128                return true;
129            }
130            catch
131            {
132                return false;
133            }
134        }
135        #endregion
136
137        loadConfigDoc#region loadConfigDoc
138        private XmlDocument loadConfigDoc( XmlDocument cfgDoc )
139        {
140            // load the config file   
141            if(  Convert.ToInt32(ConfigType)==Convert.ToInt32(ConfigFileType.AppConfig))
142            {
143                docName= ((Assembly.GetEntryAssembly()).GetName()).Name;
144                docName +=   ".exe.config";
145            }
146            else
147            {
148                docName=HttpContext.Current.Server.MapPath("web.config");
149            }
150            cfgDoc.Load( docName );
151            return cfgDoc;
152        }
153        #endregion
154    }
155}