C＃XML反序列化不返回列表类型的任何元素

Question

提到question时，我曾问过有关XML反序列化的信息。

XML对象：

[XmlRoot(ElementName = "root")]
public class RootMIR
{
    [XmlArray(ElementName = "MIRs")]
    public List<MIR> MIRs { get; set; }
}



[XmlRoot(ElementName = "MIR")]
public class MIR
{
    [XmlElement(ElementName = "issue_data")]
    public IssueData IssueData { get; set; }

    [XmlElement(ElementName = "reply_data")]
    public ReplyData ReplyData { get; set; }

    [XmlElement(ElementName = "receive_data")]
    public ReceiveData ReceiveData { get; set; }

    /*[XmlElement(ElementName = "items")]
    public Items Items { get; set; }*/

    [XmlArray(ElementName = "items")]
    public List<Item> Items { get; set; }

    [XmlElement(ElementName = "submission_data")]
    public SubmissionData SubmissionData { get; set; }

    [XmlIgnore]
    public int ID { get; set; }
    [XmlAttribute(AttributeName = "id")]
    public string ID_text
    {
        get { return ID.ToString(); }
        set { ID = Convert.ToInt32(value); }
    }


    [XmlAttribute(AttributeName = "number")]
    public string _numberText;
    [XmlIgnore]
    public int? Number
    {
        get { return _numberText == "" ? (int?)null : Convert.ToInt32(_numberText); }
        set { _numberText = value == null ? "" : value.ToString(); }
    }
    /*[XmlIgnore]
    public int? Number
    {
        get { return Number_text == "" ? (int?)null : Convert.ToInt32(Number_text); }
        set { Number_text = value.ToString(); }
    }
    [XmlAttribute(AttributeName = "number")]
    public string Number_text { get; set; }*/


    [XmlIgnore]
    public int? Revision
    {
        get { return Revision_text == "" ? (int?)null : Convert.ToInt32(Revision_text); }
        set { Revision_text = value == null ? "" : value.ToString(); }
    }
    [XmlAttribute(AttributeName = "revision")]
    public string Revision_text { get; set; }

}



[XmlRoot(ElementName = "issue_data")]
public class IssueData
{
    [XmlIgnore]
    public DateTime? IssueDate { get; set; }
    [XmlElement(ElementName = "issue_date")]
    public string IssueDateText
    {
        get { return (IssueDate.HasValue ? IssueDate.ToString() : null); }
        set { IssueDate = Convert.ToDateTime(value); }
    }


    [XmlElement(ElementName = "from")]
    public string From { get; set; }


    [XmlElement(ElementName = "to")]
    public string To { get; set; }


    [XmlElement(ElementName = "author")]
    public string Author { get; set; }


    [XmlElement(ElementName = "attn")]
    public string Attn { get; set; }


    [XmlElement(ElementName = "field")]
    public string Field { get; set; }


    [XmlElement(ElementName = "material_group")]
    public string MaterialGroup { get; set; }


    [XmlElement(ElementName = "related_sub")]
    public string RelatedSub { get; set; }
}



[XmlRoot(ElementName = "reply_data")]
public class ReplyData
{
    [XmlElement(ElementName = "reply_date")]
    public string ReplyDate { get; set; }

    [XmlElement(ElementName = "action_code")]
    public string ActionCode { get; set; }

    [XmlElement(ElementName = "reply_from")]
    public string ReplyFrom { get; set; }
}



[XmlRoot(ElementName = "receive_data")]
public class ReceiveData
{
    [XmlElement(ElementName = "receive_date")]
    public string ReceiveDate { get; set; }

    [XmlElement(ElementName = "receive_by")]
    public string ReceiveBy { get; set; }
}



[XmlRoot(ElementName = "item")]
public class Item
{
    [XmlElement(ElementName = "serial")]
    public string Serial { get; set; }

    [XmlElement(ElementName = "boq_code")]
    public string BoqCode { get; set; }

    [XmlElement(ElementName = "item_details")]
    public string ItemDetails { get; set; }

    [XmlElement(ElementName = "model")]
    public string Model { get; set; }

    [XmlElement(ElementName = "manufacturer")]
    public string Manufacturer { get; set; }

    [XmlElement(ElementName = "size")]
    public string Size { get; set; }

    [XmlElement(ElementName = "uom")]
    public string UoM { get; set; }

    [XmlElement(ElementName = "qty")]
    public string Quantity { get; set; }

    [XmlElement(ElementName = "approval")]
    public string Approval { get; set; }

    [XmlElement(ElementName = "approved_qty")]
    public string ApprovedQuantity { get; set; }

    [XmlElement(ElementName = "is_lumbsum")]
    public string IsLumbsum { get; set; }
}



[XmlRoot(ElementName = "submission_data")]
public class SubmissionData
{
    //[XmlElement(ElementName = "submitted")]
    //public string Submitted { get; set; }

    [XmlElement(ElementName = "status")]
    public string Status { get; set; }
}

对于序列化器对象，

代码：

public static void ReloadDocumentFromDisk()
{
    using (FileStream fileStream = new FileStream(BaseDir + FileName + Extension, FileMode.Open))
    {
        DocMIR = (RootMIR)serializer.Deserialize(fileStream);
    }
}

问题是我收到List<Item>的空白列表，但是List<MIR>正常运行，我检查了很多遍代码，但没有发现我所缺少的是什么。

这是我添加断点以检查代码的结果：

MIR的数量为10，因为我的XML文件中有10个元素，但是每个MIR中的项目数为0

Answer 1

您需要使用XmlArrayItem属性来指示每个“项目”的元素名称都与您要反序列化的Item的类名称不同。

[XmlArray(ElementName = "items")]
[XmlArrayItem(ElementName = "item")]
public List<Item> Items { get; set; }

如果您的Item类被称为item，那么在没有XmlArrayItem的情况下可以正常工作。这就是为什么仅在使用MIR属性时，您对MIRs属性使用XmlArray可以正常工作的原因，因为内部元素的类名完全匹配。

Answer 2

日期时间不能为null。因此，您需要能够处理datetime为null的情况。所以我做了一个新的DateTime（）。请参阅下面我用您的xml测试过的代码

注意：您在以前的帖子中回答了您一个问题，即如何使用Xml Linq使用匿名解析来解析xml。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.Globalization;

namespace ConsoleApplication1
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(FILENAME);
            IFormatProvider provider = CultureInfo.InvariantCulture;
            var results = doc.Descendants("MIR").Select(mir => new
            {
                Number = (string)mir.Attribute("number"),
                Revision = (string)mir.Attribute("revision"),
                From = (string)mir.Element("issue_data").Element("from"),
                Material = (string)mir.Element("issue_data").Element("material_group"),
                Field = (string)mir.Element("issue_data").Element("field"),
                Submittal = (string)mir.Element("issue_data").Element("related_sub"),
                To = (string)mir.Element("issue_data").Element("to"),
                Atten = (string)mir.Element("issue_data").Element("attn"),
                IssueDate =   DateTime.ParseExact((string)mir.Descendants("issue_date").FirstOrDefault(), "dd-M-yyyy",provider),
                ReplyDate = (string)mir.Descendants("receive_date").FirstOrDefault() == string.Empty ? new DateTime() : DateTime.ParseExact((string)mir.Descendants("receive_date").FirstOrDefault(), "dd-M-yyyy", provider),
                ActionCode = (string)mir.Element("reply_data").Element("action_code"),
                Author = (string)mir.Element("issue_data").Element("author"),
                IsSubmitted = (string)mir.Element("submission_data").Element("submitted"),
                Status = (string)mir.Element("submission_data").Element("status")
            }).First();
        }
    }
}