反序列化为列表

本文关键字：列表 反序列化 | 更新日期: 2023-09-27 18:13:40

我正在使用XmlSerializer.Serialize和XmlSerializer.Deserialize我有一个类MetricResult:

public   class Metricresult
{
        public string metric;
        public string newvalue;
        public string deltavalue;
}

，我正在计算一些结果，这些结果将存储在:

List<Metricresult> metricresults = new List<Metricresult>();

我成功地将这个列表更改为XML文件，在另一个项目中，我需要反序列化这个列表，但有一个异常抛出:

there-is-an-error-in-xml-document-0-0-during-deserialization


<?xml version="1.0" encoding="utf-8"?>
<ArrayOfMetricresult xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Metricresult>
    <metric>numberofdeclaration</metric>
    <newvalue>0</newvalue>
    <deltavalue>0</deltavalue>
  </Metricresult>
  <Metricresult>
    <metric>numberofdeclaration</metric>
    <newvalue>0</newvalue>
    <deltavalue>0</deltavalue>
  </Metricresult>
  <Metricresult>
    <metric>numberofdeclaration</metric>
    <newvalue>0</newvalue>
    <deltavalue>0</deltavalue>
  </Metricresult>
  <Metricresult>
    <metric>numberofdeclaration</metric>
    <newvalue>0</newvalue>
    <deltavalue>0</deltavalue>
  </Metricresult>
  <Metricresult>
    <metric>numberofdeclaration</metric>
    <newvalue>0</newvalue>
    <deltavalue>0</deltavalue>
  </Metricresult>
  <Metricresult>
    <metric>numberofdeclaration</metric>
    <newvalue>0</newvalue>
    <deltavalue>0</deltavalue>
  </Metricresult>
</ArrayOfMetricresult>

反序列化为列表

奇怪，因为下面的内容对我来说很好:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml;
using System.Xml.Serialization;
public class MetricResult
{
    public string Metric { get; set; }
    public string NewValue { get; set; }
    public string DeltaValue { get; set; }
}
class Program
{
    static void Main()
    {
        // define some metric results to serialize
        var metricResults = new[] 
        { 
            new MetricResult { Metric = "metric 1", NewValue = "new value 1", DeltaValue = "delta 1" },
            new MetricResult { Metric = "metric 2", NewValue = "new value 2", DeltaValue = "delta 2" },
            new MetricResult { Metric = "metric 3", NewValue = "new value 3", DeltaValue = "delta 3" },
        }.ToList();
        var serializer = new XmlSerializer(metricResults.GetType());
        using (var writer = XmlWriter.Create("metrics.xml"))
        {
            // serialize the metric results we defined previously to metrics.xml
            serializer.Serialize(writer, metricResults);
        }
        using (var reader = XmlReader.Create("metrics.xml"))
        {
            // read metrics.xml and deserialize back
            metricResults = (List<MetricResult>)serializer.Deserialize(reader);
            foreach (var result in metricResults)
            {
                Console.WriteLine("metric: {0}, new value: {1}, delta: {2}", result.Metric, result.NewValue, result.DeltaValue);
            }
        }
    }
}

和metrics.xml看起来像预期的:

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfMetricResult xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <MetricResult>
    <Metric>metric 1</Metric>
    <NewValue>new value 1</NewValue>
    <DeltaValue>delta 1</DeltaValue>
  </MetricResult>
  <MetricResult>
    <Metric>metric 2</Metric>
    <NewValue>new value 2</NewValue>
    <DeltaValue>delta 2</DeltaValue>
  </MetricResult>
  <MetricResult>
    <Metric>metric 3</Metric>
    <NewValue>new value 3</NewValue>
    <DeltaValue>delta 3</DeltaValue>
  </MetricResult>
</ArrayOfMetricResult>

0,0的错误通常意味着在xml文件的开头，在第一个元素之前有空白。仔细查看xml(可能查看二进制，而不是文本-它也可能是unicode不可见的空格，等等)。

也:每当使用XmlSerializer时，请查看InnerException s:

catch(Exception ex) {
    while(ex != null) {
        Trace.WriteLine(ex.Message);
        ex = ex.InnerException;
    }
}

通常有非常详细的解释，如果你从头到尾看一遍消息。

人们常犯的一个错误是在使用流时，不倒带。下面的语句将返回0,0错误: 
    using (var ms = new MemoryStream())
    {
        serializer.Serialize(ms, metricResults);
        serializer.Deserialize(ms);
    }

，因为序列化在最后离开了流。如果您有这样的代码，请将流重置到序列化和反序列化之间的起始位置(ms.Position = 0;)。参见:你有多少种方式可以搞砸IO?

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