How to write settings to App.config(Configuration in C# .NET 2.0)

System.Configuration.Configuration config =ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

config.AppSettings.Settings["IP"].Value = "3";
config.Save(ConfigurationSaveMode.Modified);
ConfigurationManager.RefreshSection("appSettings");

yeap this is the microsoft example. doesn't work at all. !!! dont get caught this never works. I was trying hours and hours,

use this class .



public enum ConfigFileType
{
WebConfig,
AppConfig
}

public class AppConfig : System.Configuration.AppSettingsReader
{
public string docName = String.Empty;
private XmlNode node = null;

private int _configType;
public int ConfigType
{
get
{
return _configType;
}
set
{
_configType = value;
}
}

public bool SetValue(string key, string value)
{
XmlDocument cfgDoc = new XmlDocument();
loadConfigDoc(cfgDoc);
// retrieve the appSettings node
node = cfgDoc.SelectSingleNode("//appSettings");

if (node == null)
{
throw new System.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;
}
}

private 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;
}
}

public bool removeElement(string elementKey)
{
try
{
XmlDocument cfgDoc = new XmlDocument();
loadConfigDoc(cfgDoc);
// retrieve the appSettings node
node = cfgDoc.SelectSingleNode("//appSettings");
if (node == null)
{
throw new System.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 XmlDocument loadConfigDoc(XmlDocument cfgDoc)
{
// load the config file
if (Convert.ToInt32(ConfigType) == Convert.ToInt32(ConfigFileType.AppConfig))
{

docName = ((Assembly.GetEntryAssembly()).GetName()).Name;
docName += ".exe.config";
}
else
{
// docName = System.Web.HttpContext.Current.Server.MapPath("web.config");
}
cfgDoc.Load(docName);
return cfgDoc;
}

}


==========================

Eg

AppConfig a = new AppConfig();
a.ConfigType = 1;
a.SetValue("IP", "123132123123");

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