How to save config data into an XML file

Part 1: where to save application config data
Part 2: this part, how to save data in an XML file (using XmlDocument)
Part 3: how to load (parse) an XML file

There are many different ways of working with XML files under .NET. You can hand-roll your own code, use XmlReader, use XmlDocument, use someone's third-party library, and who knows what else. I find using XmlDocument the most sensible approach -- why write my own code? I'll let someone else worry about that.

I'll just dump the code here:

public void SaveData()
{
XmlDocument doc = CreateSaveDoc();
string myAppPath = GetConfigPath();
string myAppFile = myAppPath + "/" + kConfigFile;
if (!File.Exists(myAppFile))
{
Directory.CreateDirectory(myAppPath);
}
doc.Save(myAppFile);
}

private XmlDocument CreateSaveDoc()
{
XmlDocument doc = new XmlDocument();
XmlElement root = doc.CreateElement("root");
XmlElement ints = doc.CreateElement(kIntId);
int idNum = 0;
foreach (KeyValuePair kvp in _intList)
{
string id = "int" + idNum.ToString();
++idNum;
XmlElement node = doc.CreateElement(id);
node.SetAttribute("key", kvp.Key);
node.SetAttribute("value", kvp.Value.ToString());
ints.AppendChild(node);
}
root.AppendChild(ints);
XmlElement strs = doc.CreateElement(kStrId);
int strNum = 0;
foreach (KeyValuePair kvp in _stringList)
{
string id = "str" + strNum.ToString();
++strNum;
XmlElement node = doc.CreateElement(id);
node.SetAttribute("key", kvp.Key);
node.SetAttribute("value", kvp.Value);
strs.AppendChild(node);
}
root.AppendChild(strs);
doc.AppendChild(root);
return doc;
}

I used attributes to store info, and ignored the tag names for the contained data. I think the whole 6bytes part of XML is poopy. Yes, I said it, poopy. Attributes work better for me, cuz then you get XML that looks like:

This could be shortened to:

but, well, I got it working and I stopped caring. If you implement this yourself, feel free to take that extra step.

Hmm, I say that now... ok, I went back and changed my code. This complicates loading a bit, because I now care about tags, but you'll see that in the next section. For completeness, those inner loops are now:

{
string id = kvp.Key;
XmlElement node = doc.CreateElement(id);
node.SetAttribute("value", kvp.Value);
strs.AppendChild(node);
}

Much cleaner!