Question

我有一个基类Control，它包含一个属性public ControlCollection Controls;：

public abstract class Control { 
    ...
    public virtual string Name { get: set; }
    public ControlCollection Controls;
    public Control parent = null;
    ...
}

ControlCollection是我自己的类，实现了IList<Control>：

public sealed class ControlCollection : IList<Control>, IMySerializable {       
    public int Count => _controls.Count;
    public bool IsReadOnly { get; } = false;
    public Control Parent;

    private List<Control> _controls = new List<Control>();

    public ControlCollection(Control parent) {
        Parent = parent ?? throw new ArgumentNullException("parent");
    }

    public Control this[int index] {
        get => _controls[index];
        set => _controls[index] = value;
    }

    public void Add(Control child) {
        child.parent = Parent;
        _controls.Add(child);
    }

    ...
}

如果我将属性Controls的类型从ControlCollection更改为List<Control>，则下面的代码将形成正确的XML文件

// temp data
Control rootObj = new Button();  rootObj.Name = "111";
Control obj2 = new Label();   obj2.Name = "222";
Control obj3 = new Button();  obj3.Name = "333";    
rootObj.Controls.Add(obj2); 
rootObj.Controls.Add(obj3);

List<Type> list = new List<Type>();
rootObj.Controls.ForEach(child => child.DoActionWithChildren(node => {
    list.Add(node.GetType());
}));

list.Add(typeof(Button));
list = list.Distinct().ToList();

// trying to set xml attributes. 'Controls' property will be a root of collection
var attributes = new XmlAttributes();
list.ForEach(t => attributes.XmlArrayItems.Add(new XmlArrayItemAttribute(t)));
var attrOverride = new XmlAttributeOverrides();
attrOverride.Add(typeof(Control), "Controls", attributes); 

// save data to file    
using(StreamWriter sw = new StreamWriter("path/to/xml/file.xml", false, Encoding.UTF8)) {
    XmlSerializer xs = new XmlSerializer(typeof(Control), attrOverride);        
    XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
    ns.Add(string.Empty, string.Empty);
    xs.Serialize(sw, rootObj, ns);  
}

/* ---------------------- */
output:

<?xml version="1.0" encoding="utf-8"?>
<Control d1p1:type="Button" xmlns:d1p1="http://www.w3.org/2001/XMLSchema-instance">
  <Controls>
    <Control d1p1:type="Label">
      <Controls />      
      <Name>22222</Name>
    </Control>
    <Control d1p1:type="Button">
      <Controls />
      <Name>32333</Name>      
    </Control>
  </Controls>  
  <Name>1111</Name>  
</Control>

但是如果属性Controls的类型为ControlCollection，则XML将被切断：

<?xml version="1.0" encoding="utf-8"?>
<Button>
  <Controls>
    <Control d3p1:type="Label" xmlns:d3p1="http://www.w3.org/2001/XMLSchema-instance">
      <Controls />

我尝试更改类型：attrOverride.Add(typeof(ControlCollection), "Controls", attributes);，但这不起作用。

我应该怎么做才能正确地序列化ControlCollection？然后我应该知道适当地反序列化什么？

Answer 1

好，我修复了它。事实证明，由于我的基类中有一个属性public Control parent = null;，所以我有一个循环引用。我写了一个属性[XmlIgnore]，即使使用attrOverride.Add(typeof(ControlCollection), "Controls", attributes);

，它也能正常工作

我没有看到此错误的原因是我的原始项目是 Unity 项目。而且 Unity 没有向我显示该错误。当我制作一个简单的 C＃控制台应用程序时-它向我显示了该错误。真可悲，但这是真的。

如何序列化/反序列化IList集合的类包装器？

1 个答案: