AppConfig style xml based configuration in Windows Mobile

My first surprise when I start to learn Windows Mobile programming was the lack of Application configuration. So, I would like to show a solution to this problem.

First of all, you can create a new Windows mobile Class library. Then add a new xml file into library. Set the xml file Copy to Output Directory property Copy always.

Rename the Class1.cs for example Configuration.cs. Now you've got a class library with an empty xml file and a public class file which is also empty.

Next step to write the application configuration like xml file. Use configuration and appSettings tags, like appConfig. Look at my example below:

<?xml version="1.0" encoding="utf-8" ?> <configuration> <appSettings>   ...   <add key="url" value="http://test.test:8080/example" />   ...   </appSettings> </configuration>

 

Next step to write the configuration class, which will be use the xml. Firs I use singleton pattern, to guarantee only one config of application.

public class Configuration { #region singleton   static Configuration instance = null; static readonly object padlock = new object();   Configuration() { InitConfiguration(); }   public static Configuration Instance { get { lock (padlock) { if (instance == null) { instance = new Configuration(); } return instance; } } }   #endregion   #region Constructor /// <summary> /// I use this init function to separate /// singleton logic and constuctor logic /// </summary> private void InitConfiguration() {   }   #endregion }

 

After this we need a NameValueCollection, which is hold setting into the memory. Some public property, which is good to read and write settings and a Load and Save method, which is load settings information from xml tom memory and save back, if we change something.

So these are the private fields, on for NameValuePair and one for the path of xml file:

#region private fields   private NameValueCollection _settings; private string _settingsPath;   #endregion

 

These are the properties which are gets or sets information from the NameValuePair:

#region config fields   public string ServerUri { get { return _settings.Get("url"); } set { _settings.Set("url", value); } }   #endregion

 

These are the operations which are creating date transfer between memory and xml file:

#region operators   /// <summary> /// Gets settings fields from xml file /// </summary> public static void Load() { // Get the path of the settings file. _settingsPath = Path.GetDirectoryName( System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase); _settingsPath += @"\Settings.xml";   if (!File.Exists(_settingsPath)) throw new FileNotFoundException( _settingsPath + " could not be found.");   System.Xml.XmlDocument xdoc = new XmlDocument(); xdoc.Load(_settingsPath); XmlElement root = xdoc.DocumentElement; System.Xml.XmlNodeList nodeList = root.ChildNodes.Item(0).ChildNodes;   // Add settings to the NameValueCollection. _settings = new NameValueCollection(); _settings.Add("url", nodeList.Item(4).Attributes["value"].Value); }   /// <summary> /// Save modified settings fields to xml file /// </summary> public static void Save() { XmlTextWriter tw = new XmlTextWriter(_settingsPath, System.Text.UTF8Encoding.UTF8); tw.WriteStartDocument(); tw.WriteStartElement("configuration"); tw.WriteStartElement("appSettings");   for (int i = 0; i < _settings.Count; ++i) { tw.WriteStartElement("add"); tw.WriteStartAttribute("key", string.Empty); tw.WriteRaw(_settings.GetKey(i)); tw.WriteEndAttribute();   tw.WriteStartAttribute("value", string.Empty); tw.WriteRaw(_settings.Get(i)); tw.WriteEndAttribute(); tw.WriteEndElement(); }   tw.WriteEndElement(); tw.WriteEndElement();   tw.Close(); }   #endregion

 

Don't forget, xml file is a string file, if you would like to hold another type value, for example integer, you always need type validation and explicit conversation.

It's more comfortable, if you call load method into the constructor, and call Save method into all of property setter:

#region Constructor /// <summary> /// I use this init function to separate /// singleton logic and constuctor logic /// </summary> private void InitConfiguration() { Load(); }   #endregion   #region config fields   public string ServerUri { get { return _settings.Get("url"); } set { _settings.Set("url", value); Save(); } }   #endregion

 

This solution is takes to me very comfortable to programming Windows Mobile. I hope you enjoy it, and it was useful to you!

This solution is not full of my work, some part of this solution I find on the net forums, and other blogs long time before.