无法在 C# 中反序列化 XML - 无效操作异常

Question

我有一个 C# 应用程序，它在 App.config 文件中有一个自定义的配置信息部分。此时，我能够通过代码成功加载自定义信息。但是，我也在尝试从数据库中加载相同的配置信息。为了做到这一点，我从我的App.config文件中获取了一串XML，我知道它正在工作。该 XML 字符串如下所示：

<departments>
<department id="1" name="Sporting Goods">
<products>
<product name="Basketball" price="9.99">
<add key="Color" value="Orange" />
<add key="Brand" value="[BrandName]" />
</product>
</products>
</department>
</departments>

我正在尝试将此 XML 反序列化为 C# 对象。我像这样定义这些对象：

部门.cs

public class Departments : ConfigurationSection
{
private Departments() { }
[ConfigurationProperty("", IsRequired = false, IsKey = false, IsDefaultCollection = true)]
public DepartmentItemCollection Items
{
get
{
var items = base[""] as DepartmentItemCollection;
return items;
}
set { base["items"] = value; }
}
public static Departments Deserialize(string xml)
{
Departments departments = null;
var serializer = new XmlSerializer(typeof(Departments));
using (var reader = new StringReader(xml))
{
departments = (Departments)(serializer.Deserialize(reader));
}
return departments;
}
}
[ConfigurationCollection(typeof(Department), CollectionType = ConfigurationElementCollectionType.BasicMapAlternate)]
public class DepartmentItemCollection : ConfigurationElementCollection
{
private const string ItemPropertyName = "department";
public override ConfigurationElementCollectionType CollectionType
{
get { return ConfigurationElementCollectionType.BasicMapAlternate; }
}
protected override string ElementName
{
get { return ItemPropertyName; }
}
protected override bool IsElementName(string elementName)
{
return (elementName == ItemPropertyName);
}
protected override object GetElementKey(ConfigurationElement element)
{
return ((Department)element).Name;
}
protected override ConfigurationElement CreateNewElement()
{
return new Department();
}
public override bool IsReadOnly()
{
return false;
}
}

部门.cs

public class Department : ConfigurationElement
{
public Department()
{ }
[ConfigurationProperty("id", IsRequired = false, IsKey = true)]
public int Id
{
get { return (int)(this["id"]); }
set { this["id"] = value; }
}
[ConfigurationProperty("name", IsRequired = true, IsKey = true, DefaultValue = "")]
public string Name
{
get { return (string)(this["name"]); }
set { this["name"] = value; }
}
[ConfigurationProperty("products", IsRequired = false, IsKey = false, IsDefaultCollection = false)]
public ProductCollection Products
{
get { return ((ProductCollection)(base["products"])); }
set { base["products"] = value; }
}
}

部门产品.cs

[ConfigurationCollection(typeof(Product), AddItemName = "product", CollectionType = ConfigurationElementCollectionType.BasicMapAlternate)]
public class ProductCollection: ConfigurationElementCollection
{
public override ConfigurationElementCollectionType CollectionType
{
get { return ConfigurationElementCollectionType.BasicMapAlternate; }
}
protected override string ElementName
{
get { return string.Empty; }
}
protected override bool IsElementName(string elementName)
{
return (elementName == "product");
}
protected override object GetElementKey(ConfigurationElement element)
{
return element;
}
protected override ConfigurationElement CreateNewElement()
{
return new Product();
}
protected override ConfigurationElement CreateNewElement(string elementName)
{
var product = new Product();
return product;
}
public override bool IsReadOnly()
{
return false;
}
}

部门产品.cs

public class Product : ConfigurationElement
{
public Product()
{ }
[ConfigurationProperty("name", IsRequired = true, IsKey = true, DefaultValue = "")]
public string Name
{
get { return (string)(this["name"]); }
set { this["name"] = value; }
}
[ConfigurationProperty("price", IsRequired = false)]
public decimal Price
{
get { return (decimal)(this["price"]); }
set { price["name"] = value; }
}
[ConfigurationProperty("", IsRequired = false, IsKey = false, IsDefaultCollection = true)]
public KeyValueConfigurationCollection Items
{
get
{
var items = base[""] as KeyValueConfigurationCollection;
return items;
}
set { base["items"] = value; }
}
}

当我将上面显示的 XML 传递给Departments.Deserialize方法时，我收到以下错误：

InvalidOperationException：您必须在 System.Configuration.ConfigurationLockCollection 上实现默认访问器，因为它继承自 ICollection。

如何将共享的 XML 反序列化为共享的 C# 对象？

Answer 1

我过去也有类似的问题。虽然我不知道如何处理InvalidOperationException，但我设法通过直接将类标记为IXmlSerializable

[XmlRoot("departments")]
public class Departments : ConfigurationSection, IXmlSerializable
{
//Your code here..
public XmlSchema GetSchema()
{
return this.GetSchema();
}
public void ReadXml(XmlReader reader)
{
this.DeserializeElement(reader, false);
}
public void WriteXml(XmlWriter writer)
{
this.SerializeElement(writer, false);
}
}