我可以在运行时将属性添加到一个对象的属性？ [英] Can I add attributes to an object property at runtime?

问题描述

例如我想删除或更改以下属性的属性或添加一个新的。这可能吗？

  [的XmlElement（bill_info）]
[XmlIgnore]
公共BillInfo BillInfo
{
  {返回billInfo; }
  集合{billInfo =价值; }
}
 

解决方案

（编辑 - 我误解了原来的问题）

您不能添加实际属性（它们烧入IL）;然而，随着的XmlSerializer 你没有 - 你可以在构造函数中的的XmlSerializer 提供额外的属性。你这样做，不过，需要小心一点缓存的XmlSerializer 例如，如果你这样做，否则会造成每个实例的附加组件，这是一个有点漏水。 （如果你用简单的构造函数，只需要一个它不会做这种类型的）。看<一个href=\"http://msdn.microsoft.com/en-us/library/system.xml.serialization.xmlattributeoverrides.aspx\"><$c$c>XmlAttributeOverrides.

有关的例子：

 使用系统;
使用的System.Xml.Serialization;
 公共类Person
{
    静态无效的主要（）
    {
        XmlAttributeOverrides覆盖=新XmlAttributeOverrides（）;
        XMLATTRIBUTES attribs =新XMLATTRIBUTES（）;
        attribs.XmlIgnore = FALSE;
        attribs.XmlElements.Add（新XmlElementAttribute（PERSONNAME））;
        overrides.Add（typeof运算（人），姓名，attribs）;        XmlSerializer的SER =新的XmlSerializer（typeof运算（人），覆盖）;
        人人=新的Person（）;
        person.Name =马克;
        ser.Serialize（Console.Out，人）;
    }
    私人字符串名称;
    [的XmlElement（名称）]
    [XmlIgnore]
    公共字符串名称{{返回名称; } {设置名称=值; }}
}
 

还要注意;如果XML属性只是示意性的，再有一个的第二的方式使用，增加了对有关事情的数据绑定，属性 TypeDescriptor.CreateProperty ，要么 ICustomTypeDescriptor 或 TypeDescriptionProvider 。要复杂得多比XML的情况下，恐怕 - 以及所有code不工作 - 只需$使用该组件模型C $ C

For example I want to remove or change below property attributes or add a new one. Is it possible?

[XmlElement("bill_info")]
[XmlIgnore]
public BillInfo BillInfo
{
  get { return billInfo; }
  set { billInfo = value; }
}

解决方案

(edit - I misread the original question)

You cannot add actual attributes (they are burned into the IL); however, with XmlSerializer you don't have to - you can supply additional attributes in the constructor to the XmlSerializer. You do, however, need to be a little careful to cache the XmlSerializer instance if you do this, as otherwise it will create an additional assembly per instance, which is a bit leaky. (it doesn't do this if you use the simple constructor that just takes a Type). Look at XmlAttributeOverrides.

For an example:

using System;
using System.Xml.Serialization;
 public class Person
{
    static void Main()
    {
        XmlAttributeOverrides overrides = new XmlAttributeOverrides();
        XmlAttributes attribs = new XmlAttributes();
        attribs.XmlIgnore = false;
        attribs.XmlElements.Add(new XmlElementAttribute("personName"));
        overrides.Add(typeof(Person), "Name", attribs);

        XmlSerializer ser = new XmlSerializer(typeof(Person), overrides);
        Person person = new Person();
        person.Name = "Marc";
        ser.Serialize(Console.Out, person);
    }
    private string name;
    [XmlElement("name")]
    [XmlIgnore]
    public string Name { get { return name; } set { name = value; } }
}

Note also; if the xml attributes were just illustrative, then there is a second way to add attributes for things related to data-binding, by using TypeDescriptor.CreateProperty and either ICustomTypeDescriptor or TypeDescriptionProvider. Much more complex than the xml case, I'm afraid - and doesn't work for all code - just code that uses the component-model.

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