c# - 同时编写和验证 XML

Question

我有一个 Write 方法，可以序列化使用 XmlAttributes 的对象。这是非常标准的:

private bool WriteXml(DirectoryInfo dir)
{
    var xml = new XmlSerializer(typeof (Composite));
    _filename = Path.Combine(dir.FullName, _composite.Symbol + ".xml");
    using (var xmlFile = File.Create(_filename))
    {
          xml.Serialize(xmlFile, _composite);
    }
    return true;
}

除了尝试读取我刚刚写出的文件(使用架构验证器)之外，我能否在写入 XML 时执行 XSD 验证？

我可以在将内存流写入磁盘之前弄乱它，但在 .Net 中似乎通常有一种解决大多数问题的优雅方法。

Answer 1

对于任何感兴趣的人，我都是这样做的:

public Composite Read(Stream stream)
{
    _errors = null;
    var settings = new XmlReaderSettings();
    using (var fileStream = File.OpenRead(XmlComponentsXsd))
    {
        using (var schemaReader = new XmlTextReader(fileStream))
        {
            settings.Schemas.Add(null, schemaReader);
            settings.ValidationType = ValidationType.Schema;
            settings.ValidationEventHandler += OnValidationEventHandler;
            using (var xmlReader = XmlReader.Create(stream, settings))
            {
                var serialiser = new XmlSerializer(typeof (Composite));
                return (Composite) serialiser.Deserialize(xmlReader);
            }
        }
    }
}

private ValidationEventArgs _errors = null;
private void OnValidationEventHandler(object sender, ValidationEventArgs validationEventArgs)
{
    _errors = validationEventArgs;
}

然后不是将 XML 写入文件，而是使用内存流执行如下操作:

private bool WriteXml(DirectoryInfo dir)
{
    var xml = new XmlSerializer(typeof (Composite));
    var filename = Path.Combine(dir.FullName, _composite.Symbol + ".xml");
    // first write it to memory
    var memStream = new MemoryStream();
    xml.Serialize(memStream, _composite);
    memStream.Position = 0;
    Read(memStream);
    if (_errors != null)
    {
        throw new Exception(string.Format("Error writing to {0}. XSD validation failed : {1}", filename, _errors.Message));
    }
    memStream.Position = 0;
    using (var outFile = File.OpenWrite(filename))
    {
        memStream.CopyTo(outFile);
    }
    memStream.Dispose();
    return true;
}

这样，在将任何内容写入磁盘之前，您始终会根据架构进行验证。