我正在尝试使用XmlAttributeOverrides来控制在序列化类之后哪些类属性出现在xml中。它适用于“根”类上的属性,但不适用于嵌套属性。这是一个简单的例子来说明我想要完成的任务。
我的班级层次结构如下:
public class Main
{
public string Name { get; set; }
public Location Address { get; set; }
}
public class Location
{
public string StreetAddress { get; set; }
public Contact ContactInfo{ get; set; }
}
public class Contact
{
public string PhoneNumber { get; set; }
public string EmailAddr { get; set; }
}
当我序列化Main()时,我得到这样的东西:
<Main>
<Name></Name>
<Address>
<StreetAddress></StreetAddress>
<ContactInfo>
<PhoneNumber></PhoneNumber>
<EmailAddr></EmailAddr>
</ContactInfo>
</Address>
</Main>
我能做的是使用以下名称或地址保持显示:
XmlAttributeOverrides overrides = new XmlAttributeOverrides();
XmlAttributes attribs = new XmlAttributes();
attribs.XmlIgnore = true;
attribs.XmlElements.Add(new XmlElementAttribute("Address"));
overrides.Add(typeof(Main), "Address", attribs);
xs = new XmlSerializer(typeof(Main), overrides);
我还需要做的是保持Main.Address.ContactInfo被序列化 SOMETIMES (如果它是空的)。我尝试了以下但是它们不起作用:
XmlAttributeOverrides overrides = new XmlAttributeOverrides();
XmlAttributes attribs = new XmlAttributes();
attribs.XmlIgnore = true;
attribs.XmlElements.Add(new XmlElementAttribute("ContactInfo "));
overrides.Add(typeof(Contact), "ContactInfo ", attribs);
xs = new XmlSerializer(typeof(Contact), overrides);
和...
XmlAttributeOverrides overrides = new XmlAttributeOverrides();
XmlAttributes attribs = new XmlAttributes();
attribs.XmlIgnore = true;
attribs.XmlElements.Add(new XmlElementAttribute("ContactInfo "));
overrides.Add(typeof(Main.Address.ContactInfo), "ContactInfo ", attribs);
xs = new XmlSerializer(typeof(Main.Address.ContactInfo), overrides);
我实际上已经尝试了很多,包括使用XPath语句将属性名称指定为目标,但不希望尝试失败填充此页面。我用这种方法甚至可以问这个问题吗?
答案 0 :(得分:4)
有更简单的方法来实现您的目标。
您说如果/Main/Address/ContactInfo
不包含任何数据,那么您要实现的目标是不序列化ContactInfo
。
如果您按原样保留代码,它将序列化所有Main的属性,无论它们是null还是空。第一步,您需要向所有对象添加XmlSerializerNamespaces
属性,否则每个空对象将被序列化为<myElement xsi:nil="true" />
。这可以很容易地完成,如下所示:
public MyXmlElement
{
public MyXmlElement()
{
// Add your own default namespace to your type to prevet xsi:* and xsd:*
// attributes from being generated.
this._namespaces = new XmlSerializerNamespaces(new XmlQualifiedName[] {
new XmlQualifiedName(string.Empty, "urn:myDefaultNamespace") });
}
[XmlElement("MyNullableProperty", IsNullable=false)]
public string MyNullableProperty
{
get
{
return string.IsNullOrWhiteSpace(this._myNullableProperty) ?
null : this._myNullableProperty;
}
set { this._myNullableProperty = value; }
}
[XmlNamespacesDeclaration]
public XmlSerializerNamespaces Namespaces { get { return this._namespaces; } }
private XmlSerializerNamespaces _namespaces;
}
上面的代码声明了一个Namespaces
属性,该属性包含XML对象的所有相关命名空间。您应该为所有对象提供默认命名空间(以上面的代码为模型)。这可以防止在序列化对象时输出xsi:*
和xsd:*
属性。另外,使用System.Xml.Serialization.XmlElementAttribute
指定元素不可为空。
此外,通过检查string.IsNullOrWhiteSpace(someVariable)
并返回null,然后是
完成上述操作后,属性不会被序列化。
所以,将这些全部放在一起为你的Location
课程:
public class Location
{
// You should have a public default constructor on all types for (de)sereialization.
public Location()
{
this._namespaces = new XmlSerializerNamespaces(new XmlQualifiedName[] {
new XmlQualifiedName(string.Empty, "urn:myNamespace"); // Default namespace -- prevents xsi:nil="true" from being generated, as well as xsd:* attributes.
});
}
public string StreetAddress
{
// If you don't want <StreetAddress xsi:nil="true" /> to be generated, do this:
get { return string.IsNullOrEmpty(this._streetAddress) ? null : this._streetAddress; }
// Otherwise, if you don't care, just do
// get;
// Only need to implement setter if you don't want xsi:nil="true" to be generated.
set { this._streetAddress = value; }
// Otherwise, just
// set;
}
private string _streetAddress;
[XmlElement("ContactInfo", IsNullable=false)]
public Contact ContactInfo
{
// You must definitely do this to prevent the output of ContactInfo element
// when it's null (i.e. contains no data)
get
{
if (this._contactInfo != null && string.IsNullOrWhiteSpace(this._contactInfo.PhoneNumber) && string.IsNullOrWhiteSpace(this._contactInfo.EmailAddr))
return null;
return this._contactInfo;
}
set { this._contactInfo = value; }
}
private Contact _contactInfo;
[XmlNamespacesDeclarations]
public XmlSerializerNamespaces Namespaces
{
get { return this._namespaces; }
}
private XmlSerializerNamespaces _namespaces;
}
对Location
类进行这些更改后,如果没有属性为null,空或空格,或者ContactInfo
,则不应再将空ContactInfo
属性序列化为XML本身是空的。
您应该对其他对象进行类似的更改。
有关.NET XML序列化的更多信息,请参阅我的其他stackoverflow答案:
答案 1 :(得分:4)
对于其他试图使用XmlAttributeOverrides执行此操作的人,事实证明@ user1437872非常接近找到答案。以下是忽略嵌套元素ContactInfo的覆盖代码。
$words=include('array.php');
答案 2 :(得分:0)
无需向属性添加ContactInfo元素
XmlAttributeOverrides overrides = new XmlAttributeOverrides();
XmlAttributes attribs = new XmlAttributes();
attribs.XmlIgnore = true;
overrides.Add(typeof(Address), "ContactInfo ", attribs);
xs = new XmlSerializer(typeof(Main), overrides);