c# - XML 序列化 : System. InvalidOperationException: 不是预期的

Question

我正在尝试反序列化 XML 文档，当反序列化程序在文档的中途遇到某个标记时，它会给出错误:

System.InvalidOperationException <mytagname> was not expected.

它在类中的前面有一个 [System.Xml.Serialization.XmlArrayItemAttribute("MyTagName", typeof(MediaFile))] 标记，错误只发生在这个特定的标签/类，但我找不到任何会导致这种情况发生的不同之处。有人见过这个吗？

编辑更多细节:

这是反序列化器代码:

 String xmlString = _doc.ToString();
 StringReader sr = new StringReader(xmlString);            
 XmlReader xr = XmlReader.Create(sr);
 xs = new XmlSerializer(typeof(VideoAdServingTemplate<AdNode>));
 objVast = (VideoAdServingTemplate<AdNode>)xs.Deserialize(sr);

有问题的 XML 如下所示:

<VideoAdServingTemplate xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="vast.xsd">
    <Ad id="myad">
        <InLine>
            <AdSystem>MyAdSystem</AdSystem>
            <AdTitle>Advertisement</AdTitle>
            <Description>Shamwow</Description>
            <Survey>
                <URL><![CDATA[http://www.dynamiclogic.com/tracker?campaignId=234&site=yahoo]]></URL>
            </Survey>
            <Error>
                <URL><![CDATA[http://www.primarysite.com/tracker?noPlay=true&impressionTracked=false]]></URL>
            </Error>
            <Impression>
                <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?imp]]></URL>
                <URL id="anotheradsever"><![CDATA[http://www.thirdparty.com/tracker?imp]]></URL>
            </Impression>
            <TrackingEvents>
                <Tracking event="start">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?start]]></URL>
                </Tracking>
                <Tracking event="midpoint">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?mid]]></URL>
                    <URL id="anotheradsever"><![CDATA[http://www.thirdparty.com/tracker?mid]]></URL>
                </Tracking>
                <Tracking event="firstQuartile">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?fqtl]]></URL>
                    <URL id="anotheradsever"><![CDATA[http://www.thirdparty.com/tracker?fqtl]]></URL>
                </Tracking>
                <Tracking event="thirdQuartile">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?tqtl]]></URL>
                    <URL id="anotheradsever"><![CDATA[http://www.thirdparty.com/tracker?tqtl]]></URL>
                </Tracking>
                <Tracking event="complete">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?comp]]></URL>
                    <URL id="anotheradsever"><![CDATA[http://www.thirdparty.com/tracker?comp]]></URL>
                </Tracking>
                <Tracking event="mute">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?mute]]></URL>
                </Tracking>
                <Tracking event="pause">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?pause]]></URL>
                </Tracking>
                <Tracking event="replay">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?replay]]></URL>
                </Tracking>
                <Tracking event="fullscreen">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?full]]></URL>
                </Tracking>
                <Tracking event="stop">
                    <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?stop]]></URL>
                </Tracking>
            </TrackingEvents>
            <Video>
                <Duration>00:00:15</Duration>
                <AdID>AdID</AdID>
                <VideoClicks>
                    <ClickThrough>
                        <URL id="myadsever"><![CDATA[http://www.primarysite.com/tracker?click]]></URL>
                    </ClickThrough>
                    <ClickTracking>
                        <URL id="anotheradsever"><![CDATA[http://www.thirdparty.com/tracker?click]]></URL>
                        <URL id="athirdadsever"><![CDATA[http://www.thirdparty.com/tracker?click]]></URL>
                    </ClickTracking>
                    <CustomClick>
                        <URL id="redclick"><![CDATA[http://www.thirdparty.com/tracker?click]]></URL>
                        <URL id="blueclick"><![CDATA[http://www.thirdparty.com/tracker?click]]></URL>
                    </CustomClick>
                </VideoClicks>
                <MediaFiles>
                    <MediaFile delivery="streaming" bitrate="250" width="200" height="200" type="video/x-flv">
                        <URL><![CDATA[rtmp://streamingserver/streamingpath/medium/filename.flv]]></URL>
                    </MediaFile>
<MediaFile delivery="progressive" bitrate="400" width="200" height="200" type="video/x-flv">
                        <URL><![CDATA[http://progressive.hostlocation.com//high/filename.flv]]></URL>
                    </MediaFile>
                    <MediaFile delivery="progressive" bitrate="200" width="200" height="200" type="video/x-flv">
                        <URL><![CDATA[http://progressive.hostlocation.com/progressivepath/medium/filename.flv]]></URL>
                    </MediaFile>
<!-- and a few more MediaFile tags -->
</MediaFiles>
</Video>

XML 的内容有点多，但它很大，所以我从中删减了很多。我不确定反序列化所有内容的顺序，我所知道的是我在调用 xs.Deserialize() 后看到的第一个错误是:

Unhandled Error in Silverlight 2 Application 
Code: 4004    
Category: ManagedRuntimeError       
Message: System.InvalidOperationException: There is an error in XML document (1, 7). ---> System.InvalidOperationException: <MediaFile xmlns=''> was not expected.
   at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderVideoAdServingTemplate1.Read27_VideoAdServingTemplate()
   --- End of inner exception stack trace ---
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, Object events)
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle)
   at System.Xml.Serialization.XmlSerializer.Deserialize(TextReader textReader)

没有迹象表明这是预期的或为什么这不是预期的。

实现它的类具有将标签与对象相关联的定义:

 [System.Xml.Serialization.XmlArrayItemAttribute("MediaFile", typeof(MediaFile))]
    public MediaFile[] MediaFiles
    {
        get
        {
            return this.mediaFilesField;
        }
        set
        {
            this.mediaFilesField = value;
        }
    }

我假设定义中的[]和XmlArrayItemAttribute的使用是因为连续有多个MediaFile标签，所以它们被放在一个数组中。我用 xsd.exe 生成了这段代码并对其进行了轻微修改以在 Silverlight 中工作。

Answer 1

您可能需要将 MediaFile 类型作为 KnownType 传递给序列化程序:

var knownTypes = new Type[] { typeof(MediaFile) };
xs = new XmlSerializer(typeof(VideoAdServingTemplate<AdNode>), knownTypes);

否则序列化器不知道这个新类型。