XMLファイルの操作

下記の3つの方法がある。

Linq to XML

XMLに保存

var option = new XElement("option");
option.SetElementValue("enabled", true);
var root = new XElement("settings", option);
root.Save("settings.xml");

XMLの読込

var xdoc = XDocument.Load("item.xml");
var xelements = xdoc.Root.Elements();
foreach(var item in xelements)
{
    XElement xname = item.Element("name");
    System.Diagnostics.Debug.WriteLine(xname.Value);
}

名前空間がついている場合

xdoc.Root.Name.Namespaceで名前空間を取得し、要素取得時に指定する。

コレクションをXMLに保存

var items = new List<Item>()
{
    new Item()
    {
        Id = 1,
        Name = "テレビ"
    },
    new Item()
    {
        Id = 2,
        Name = "ラジオ"
    }
};

var elements = items.Select(x => 
    new XElement("item",
        new XElement("id", x.Id),
        new XElement("name", x.Name)));
var root = new XElement("items", elements);
var xdoc = new XDocument(root);

xdoc.Save("item.xml");

DataContractSerializer

XMLに保存

var item = new Item()
{
    Id = 3,
    Name = "PC"
};
var settings = new XmlWriterSettings()
{
    Encoding = new UTF8Encoding(false),
    Indent = true,
    IndentChars = "    "
};

using (var writer = XmlWriter.Create("item.xml", settings))
{
    var serializer = new DataContractSerializer(item.GetType());
    serializer.WriteObject(writer, item);
}

XMLの読込

using (var reader = XmlReader.Create("item.xml"))
{
    var serializer = new DataContractSerializer(typeof(Item));
    var item = serializer.ReadObject(reader) as Item;
    System.Diagnostics.Debug.WriteLine(item.Name);
}

XmlSerializer

XMLに保存

var item = new Item()
{
    Id = 4,
    Name = "スマホ"
};

using (var writer = XmlWriter.Create("item.xml"))
{
    var serializer = new XmlSerializer(item.GetType());
    serializer.Serialize(writer, item);
}

XMLの読込

using (var reader = XmlReader.Create("item.xml"))
{
    var serializer = new XmlSerializer(typeof(Item));
    var item = serializer.Deserialize(reader) as Item;
    System.Diagnostics.Debug.WriteLine(item.Name);
}