C# 确定类如何反序列化XML的最有效方法
我有许多xml模式的.xsd文件 范例 xml1.0-XML\u 1\u 0.XMLC# 确定类如何反序列化XML的最有效方法,c#,xml,serialization,xsd,C#,Xml,Serialization,Xsd,我有许多xml模式的.xsd文件 范例 xml1.0-XML\u 1\u 0.XML <?xml version="1.0" encoding="UTF-8"?> <cars version="1.00"> <car>Honda</car> <car>Ferrari</car> </cars> <?xml version="1.0" encoding
<?xml version="1.0" encoding="UTF-8"?>
<cars version="1.00">
<car>Honda</car>
<car>Ferrari</car>
</cars>
<?xml version="1.0" encoding="UTF-8"?>
<cars version="2.00">
<car>
<name>Honda</name>
<color>White</color>
</car>
<car>
<name>Honda</name>
<color>Red</color>
</car>
</cars>
然后像这样反序列化:
foreach(string file in files) {
XmlDocument doc = new XmlDocument();
doc.Load(file);
string version = doc.SelectSingleNode("/Cars/@version").Value;
if(version == "1.00")
{
Stream reader = new FileStream(file, FileMode.Open);
XmlSerializer serializer = new XmlSerializer(typeof(v1.Cars));
v1.Cars XML = new v1.Cars();
XML = (v1.Cars)serializer.Deserialize(reader);
}
else if(version == "2.00")
{
Stream reader = new FileStream(file, FileMode.Open);
XmlSerializer serializer = new XmlSerializer(typeof(v2.Cars));
v2.Cars XML = new v2.Cars();
XML = (v2.Cars)serializer.Deserialize(reader);
}
}
有人知道更好的方法吗,或者有更好的性能吗?您有几个选择,这取决于您想走多远。一个相当非侵入性的选择是不使用
XmlDocument
,并避免多次加载流。例如,可以将现有代码简化为:
foreach (string file in files)
{
using (var stream = new FileStream(file, FileMode.Open))
{
var settings = new XmlReaderSettings();
settings.CloseInput = false;
string version = "";
using (var xmlReader = XmlReader.Create(stream))
{
if (xmlReader.ReadToFollowing("Cars"))
{
version = xmlReader.GetAttribute("version");
}
else
{
throw new XmlException("Could not get 'version' attribute of 'Cars' root element!");
}
}
stream.Position = 0;
if (version == "1.00")
{
XmlSerializer serializer = new XmlSerializer(typeof(v1.Cars));
v1.Cars XML = new v1.Cars();
XML = (v1.Cars)serializer.Deserialize(stream);
}
else if (version == "2.00")
{
XmlSerializer serializer = new XmlSerializer(typeof(v2.Cars));
v2.Cars XML = new v2.Cars();
XML = (v2.Cars)serializer.Deserialize(stream);
}
}
}
由于您只是读取根元素,您甚至可以从XmlReader
进行反序列化,而不必重置文件流上的位置
这避免了两次加载整个文件的开销(一次用于XmlDocument
,另一次用于XmlSerializer
),尤其避免了为每个文档创建DOM的内存开销
一个更核心的选项是在一组自定义类上实现IXmlSerializable
,这些自定义类在ReadXml
方法中具有自定义逻辑,以解析版本属性并实例化正确的子类型,例如具有List
属性的CarCollection
类,其中,Car
是一个抽象类,其子类为CarV1
和CarV2
。这将尽可能地提高效率(并提供对类层次结构设计的细粒度控制),但将消除使用xsd.exe生成类的可能性。您可以共享实际的xsd吗?修改XSD是一个选项吗?创建一个新类是一种选择吗?在我编写的问题中,仅举一个例子,xsd文件要复杂得多,任何版本的xml都有许多其他属性
foreach (string file in files)
{
using (var stream = new FileStream(file, FileMode.Open))
{
var settings = new XmlReaderSettings();
settings.CloseInput = false;
string version = "";
using (var xmlReader = XmlReader.Create(stream))
{
if (xmlReader.ReadToFollowing("Cars"))
{
version = xmlReader.GetAttribute("version");
}
else
{
throw new XmlException("Could not get 'version' attribute of 'Cars' root element!");
}
}
stream.Position = 0;
if (version == "1.00")
{
XmlSerializer serializer = new XmlSerializer(typeof(v1.Cars));
v1.Cars XML = new v1.Cars();
XML = (v1.Cars)serializer.Deserialize(stream);
}
else if (version == "2.00")
{
XmlSerializer serializer = new XmlSerializer(typeof(v2.Cars));
v2.Cars XML = new v2.Cars();
XML = (v2.Cars)serializer.Deserialize(stream);
}
}
}