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为什么由于根元素中的前缀而无法反序列化XML字符串?

xml-deserialization xmlserializer xml .net c#

Natalie Perret · 技术社区 · 6 年前

我有以下XML:

<y:input xmlns:y='http://www.blahblah.com/engine/42'>
    <y:datas>
        <y:instance yclass='ReportPeriod' yid="report">
            <language yid='en'/>
            <threshold>0.6</threshold>
            <typePeriod>predefinedPeriod</typePeriod>
            <interval>month</interval>
            <valuePeriod>April</valuePeriod>
            <fund yclass="Fund">
                <name>K</name>
                <indexName>CAC40</indexName>
            </fund>
        </y:instance>
    </y:datas>
</y:input>

我试图去反序列化

[XmlRoot(ElementName="fund")]
public class Fund 
{
    [XmlElement(ElementName="name")]
    public string Name { get; set; }

    [XmlElement(ElementName="indexName")]
    public string IndexName { get; set; }

    [XmlAttribute(AttributeName="yclass")]
    public string Yclass { get; set; }
}

[XmlRoot(ElementName="instance", Namespace="http://www.blahblah.com/engine/42")]
public class Instance 
{
    [XmlElement(ElementName="language")]
    public Language Language { get; set; }

    [XmlElement(ElementName="threshold")]
    public string Threshold { get; set; }

    [XmlElement(ElementName="typePeriod")]
    public string TypePeriod { get; set; }

    [XmlElement(ElementName="interval")]
    public string Interval { get; set; }

    [XmlElement(ElementName="valuePeriod")]
    public string ValuePeriod { get; set; }

    [XmlElement(ElementName="fund")]
    public Fund Fund { get; set; }

    [XmlAttribute(AttributeName="yclass")]
    public string Yclass { get; set; }

    [XmlAttribute(AttributeName="yid")]
    public string Yid { get; set; }
}

[XmlRoot(ElementName="datas", Namespace="http://www.blahblah.com/engine/42")]
public class Datas
{
    [XmlElement(ElementName="instance", Namespace="http://www.blahblah.com/engine/42")]
    public Instance Instance { get; set; }
}

[XmlRoot(ElementName="input", Namespace="http://www.blahblah.com/engine/42")]
public class Input
{
    [XmlElement(ElementName="datas", Namespace="http://www.blahblah.com/engine/42")]
    public Datas Datas { get; set; }

    [XmlAttribute(AttributeName="y", Namespace="http://www.blahblah.com/engine/42", Form = XmlSchemaForm.Qualified)]
    public string Y { get; set; }
}

public static class Program
{
    public static void Main(params string[] args)
    {
        var serializer = new XmlSerializer(typeof(Input));
        using (var stringReader = new StringReader(File.ReadAllText("file.xml")))
        {
            using(var xmlReader = XmlReader.Create(stringReader))
            {
                var instance = (Input)serializer.Deserialize(stringReader);
            }
        }
    }
}

我得到一个错误是由于 y 前缀。。。

There is an error in XML document (1, 1). ---> System.Xml.XmlException: Data at the root level is invalid. Line 1, position 1.

读一些像这样的帖子: https://stackoverflow.com/a/36163079/4636721 好像有个虫子 XmlSerializer .

1 回复 | 直到 6 年前

dbc 6 年前

异常的原因是 stringReader xmlReader 到 serializer.Deserialize() . 您应该传递XML读取器:

Input instance = null;
var serializer = new XmlSerializer(typeof(Input));
using (var stringReader = new StreamReader("file.xml"))
{
    using(var xmlReader = XmlReader.Create(stringReader))
    {
        instance = (Input)serializer.Deserialize(xmlReader);
    }
}

(显然 XmlReader.Create(stringReader) 使文本读取器前进一点,因此如果稍后尝试从 字符串读取器

数据模型中也有一些错误。它应该看起来像:

[XmlRoot(ElementName="fund")]
public class Fund 
{
    [XmlElement(ElementName="name")]
    public string Name { get; set; }

    [XmlElement(ElementName="indexName")]
    public string IndexName { get; set; }

    [XmlAttribute(AttributeName="yclass")]
    public string Yclass { get; set; }
}

[XmlRoot(ElementName="instance")]
[XmlType(Namespace = "")] // Add this
public class Instance 
{
    [XmlElement(ElementName="language")]
    public Language Language { get; set; }

    [XmlElement(ElementName="threshold")]
    public string Threshold { get; set; }

    [XmlElement(ElementName="typePeriod")]
    public string TypePeriod { get; set; }

    [XmlElement(ElementName="interval")]
    public string Interval { get; set; }

    [XmlElement(ElementName="valuePeriod")]
    public string ValuePeriod { get; set; }

    [XmlElement(ElementName="fund")]
    public Fund Fund { get; set; }

    [XmlAttribute(AttributeName="yclass")]
    public string Yclass { get; set; }

    [XmlAttribute(AttributeName="yid")]
    public string Yid { get; set; }
}

[XmlRoot(ElementName="datas", Namespace="http://www.blahblah.com/engine/42")]
public class Datas
{
    [XmlElement(ElementName="instance", Namespace="http://www.blahblah.com/engine/42")]
    public Instance Instance { get; set; }
}

[XmlRoot(ElementName="input", Namespace="http://www.blahblah.com/engine/42")]
public class Input
{
    [XmlElement(ElementName="datas", Namespace="http://www.blahblah.com/engine/42")]
    public Datas Datas { get; set; }

    //Remove This
    //[XmlAttribute(AttributeName="y", Namespace="http://www.blahblah.com/engine/42", Form = XmlSchemaForm.Qualified)]
    //public string Y { get; set; }
}

// Add this
[XmlRoot(ElementName="language")]
public class Language 
{
    [XmlAttribute(AttributeName="yid")]
    public string Yid { get; set; }
}

笔记:

xmlns:y='http://www.blahblah.com/engine/42' XML namespace declaration 因此不应映射到数据模型中的成员。
的子元素 <y:instance ...> XmlSerializer 假设它们应该与包含元素在同一个命名空间中,这里 http://www.blahblah.com/engine/42" .

因此有必要补充 [XmlType(Namespace = "")] Instance 为从中创建的所有子元素指示正确的命名空间 . (另一个选择是 [XmlElement(Form = XmlSchemaForm.Unqualified)]
对…的定义 Language 不包括在你的问题里,所以我包括了一个。
StreamReader 而不是先读到 string ,然后从使用 StringReader .

工作样品小提琴 here