Had a delegate of mine ask the same question recently - here's my reply.
(key point is System.Windows.Forms.Application.*UserAppDataPath* property
which is designed especially for user-specific application settings):
------
A couple of guidelines. If you are storing user preferences then the
application config file is *not* the right place. You should store it in
the user's profile which is somewhere like:
C:\Documents and Settings\<username>\Application Data
Here you can store any sort of "settings file" you like - it doesn't have
to be in any particular format. What I have done in the past is have a
couple of routines save and load a dictionary (StringCollection) to and
from and XML file (note: you could use
System.Xml.Serialization.XmlSerializer to do this for you). To help you
with this you have the System.Windows.Forms.Application.UserAppDataPath
property (it will create the path if it doesn't exist) and then in that
folder you can stick what you like. This setting should roam with the user
in a properly configured Windows network.
Here's some routines from a project I've done recently: they load and save
a StringCollection to/from a file called "ui.config" in the user's profile:
==============================================
/*********************************************************************/
private void saveAppSettings( StringDictionary settings ) {
string appPath = Application.UserAppDataPath;
string configFileName = Path.Combine(appPath, "ui.config");
XmlDocument appSettingsDoc = new XmlDocument();
XmlNode root = appSettingsDoc.AppendChild(appSettingsDoc.CreateNode
(XmlNodeType.Element, "Settings", null));
foreach(string settingName in settings.Keys) {
XmlElement setting = appSettingsDoc.CreateElement
("Setting");
setting.SetAttribute("name", settingName);
setting.SetAttribute("value", settings[settingName]);
root.AppendChild(setting);
}
appSettingsDoc.Save(configFileName);
}
/*********************************************************************/
private StringDictionary loadAppSettings () {
string appPath = Application.UserAppDataPath;
string configFileName = Path.Combine(appPath, "ui.config");
XmlDocument appSettingsDoc = new XmlDocument();
appSettingsDoc.Load(configFileName);
StringDictionary settings = new StringDictionary();
foreach(XmlNode setting in appSettingsDoc.SelectNodes
("Settings/Setting")) {
string name = setting.Attributes.GetNamedItem
("name").Value;
string value = setting.Attributes.GetNamedItem
("value").Value;
settings[name] = value;
}
return settings;
}
==============================================
If you really want to write to the application's config file then do
something like this:
==============================================
void saveSetting(string key, string value) {
//find config file
string configFilePath = Application.ExecutablePath + ".config";
//load up into XML DOM
XmlDocument configDoc = new XmlDocument();
configDoc.Load(configFilePath);
//locate nodes of interest
XmlNode appSettingsNode = configDoc.SelectSingleNode
("/configuration/appSettings");
//TODO: create 'appSettings' node if it doesn't exist
//Find node they're after
XmlNode settingNode = appSettingsNode.SelectSingleNode("add
[@key='"+key+"']");
//If found: set the value; if not: create it
if(settingNode!=null) {
settingNode.Attributes["value"].Value = value;
} else {
XmlElement addElement = configDoc.CreateElement("add");
addElement.SetAttribute("key", key);
addElement.SetAttribute("value", value);
configDoc.SelectSingleNode
("/configuration/appSettings").AppendChild(addElement);
}
//Save and done
configDoc.Save(configFilePath);
}
=====================================
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