XML反序列化为C#类时UOMS等部分元素无法正常加载

尝试将XML反序列化为C#类时，大部分元素能正常加载，但XML中的UOMS对象始终无法被反序列化——无报错，但UOMS对象仅为默认值。试过在线XML转C#工具、[XmlArray]/[XmlArrayItem]特性均未解决问题。

示例XML #

<Items xmlns="http://www.manh.com/ILSNET/Interface" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <Item>
        <Desc>Desc Field Example Value</Desc>
        <Item>PE0000009790</Item>
        <ItemCategories>
            <Action>SAVE</Action>
            <Category1>COMPONENT</Category1>
            <Category2>Category2ExampleValue</Category2>
        </ItemCategories>
        <ItemClass>
            <Action>SAVE</Action>
            <ItemClass>Example ItemClass</ItemClass>
        </ItemClass>
        <UOMS>
            <UOM>
                <Action>SAVE</Action>
                <ConvQty>1</ConvQty>
                <DimensionUm>IN</DimensionUm>
                <Height>0.0</Height>
                <Length>0.0</Length>
                <QtyUm>EA</QtyUm>
                <Sequence>1</Sequence>
                <Weight>0</Weight>
                <WeightUm>LB</WeightUm>
                <Width>0.0</Width>
            </UOM>
        </UOMS>
    </Item>
</Items>

现有代码 #

基础反序列化代码 #

using (FileStream fileStream = new FileStream(Filename, FileMode.Open))
{
    this.CreatedObjects = (ItemList)serializer.Deserialize(fileStream);
}

第一部分类定义 #

[XmlRoot(ElementName = "Items", Namespace = "http://www.manh.com/ILSNET/Interface")]
public class ItemList
{
    [XmlElement("Item")]
    public Item[] Items { get; set; }
}

public class Item
{
    [XmlElement("ItemCategories")]
    public ItemCategory[] Categories { get; set; }

    [XmlElement("ItemClass")]
    public ItemClass[] Classes { get; set; }

    [XmlElement("UOMS")]
    public ItemUOMS UOMs { get; set; }

    [XmlElement("Desc")]
    public string Description { get; set; }

    [XmlElement("Item")]
    public string Id { get; set; }
}

无法填充的第二部分类定义 #

[XmlRoot(ElementName = "UOMS", Namespace = "http://www.manh.com/ILSNET/Interface")]
public class ItemUOMS
{
    [XmlElement("UOM")]
    public ItemUOM[] UOM { get; set; }
}

[XmlRoot(ElementName = "UOM", Namespace = "http://www.manh.com/ILSNET/Interface")]
public class ItemUOM
{
    [XmlElement("Action")]
    public string Action { get; }

    [XmlElement("DimensionUm")]
    public string DimensionUnit { get; }

    [XmlElement]
    public decimal Height { get; }

    [XmlElement]
    public decimal Length { get; }

    [XmlElement("QtyUm")]
    public string QtyUnit { get; }

    [XmlElement("ConvQty")]
    public decimal Quantity { get; }

    [XmlElement]
    public int Sequence { get; }

    [XmlElement]
    public decimal Weight { get; }

    [XmlElement("WeightUm")]
    public string WeightUnit { get; }

    [XmlElement]
    public decimal Width { get; }
}

解决方案 #

问题出在三个关键点，逐一修复即可：

1. 命名空间未统一
   XML中所有元素都属于http://www.manh.com/ILSNET/Interface命名空间，但Item类中的UOMs属性未指定命名空间，导致反序列化器无法匹配元素。可以给Item类添加[XmlType]指定命名空间，确保所有嵌套类继承该命名空间：

   [XmlType(Namespace = "http://www.manh.com/ILSNET/Interface")]
   public class Item
   {
       // 原有属性代码...
   }
   

   或者给UOMs属性的[XmlElement]显式指定命名空间：

   [XmlElement("UOMS", Namespace = "http://www.manh.com/ILSNET/Interface")]
   public ItemUOMS UOMs { get; set; }
   

2. ItemUOM类属性只有getter
   XML反序列化需要属性具备公共setter才能赋值，把ItemUOM中的所有只读属性修改为带setter的形式：

   [XmlElement("Action")]
   public string Action { get; set; }
   
   [XmlElement("DimensionUm")]
   public string DimensionUnit { get; set; }
   
   // 其他属性同理修改...
   

3. [XmlRoot]特性误用
   ItemUOMS和ItemUOM不是根元素，不需要[XmlRoot]特性，直接移除即可，改用[XmlType]（可选，用于指定命名空间）：

   [XmlType(Namespace = "http://www.manh.com/ILSNET/Interface")]
   public class ItemUOMS
   {
       [XmlElement("UOM")]
       public ItemUOM[] UOM { get; set; }
   }
   
   [XmlType(Namespace = "http://www.manh.com/ILSNET/Interface")]
   public class ItemUOM
   {
       // 修改后的属性代码...
   }
   

修复后的完整类代码示例 #

[XmlRoot(ElementName = "Items", Namespace = "http://www.manh.com/ILSNET/Interface")]
public class ItemList
{
    [XmlElement("Item")]
    public Item[] Items { get; set; }
}

[XmlType(Namespace = "http://www.manh.com/ILSNET/Interface")]
public class Item
{
    [XmlElement("ItemCategories")]
    public ItemCategory[] Categories { get; set; }

    [XmlElement("ItemClass")]
    public ItemClass[] Classes { get; set; }

    [XmlElement("UOMS")]
    public ItemUOMS UOMs { get; set; }

    [XmlElement("Desc")]
    public string Description { get; set; }

    [XmlElement("Item")]
    public string Id { get; set; }
}

[XmlType(Namespace = "http://www.manh.com/ILSNET/Interface")]
public class ItemUOMS
{
    [XmlElement("UOM")]
    public ItemUOM[] UOM { get; set; }
}

[XmlType(Namespace = "http://www.manh.com/ILSNET/Interface")]
public class ItemUOM
{
    [XmlElement("Action")]
    public string Action { get; set; }

    [XmlElement("DimensionUm")]
    public string DimensionUnit { get; set; }

    [XmlElement("Height")]
    public decimal Height { get; set; }

    [XmlElement("Length")]
    public decimal Length { get; set; }

    [XmlElement("QtyUm")]
    public string QtyUnit { get; set; }

    [XmlElement("ConvQty")]
    public decimal Quantity { get; set; }

    [XmlElement("Sequence")]
    public int Sequence { get; set; }

    [XmlElement("Weight")]
    public decimal Weight { get; set; }

    [XmlElement("WeightUm")]
    public string WeightUnit { get; set; }

    [XmlElement("Width")]
    public decimal Width { get; set; }
}

内容的提问来源于stack exchange，提问作者Nick