序列化可观察集合时出错
本文关键字：出错 集合 观察 序列化 | 更新日期: 2023-09-27 18:33:50
我有一个可观察的集合，我正在尝试序列化到磁盘。 收到的错误是：
Type 'VisuallySpeaking.Data.GrammarList' with data contract name
'GrammarList:http://schemas.datacontract.org/2004/07/VisuallySpeaking.Data'
is not expected. Consider using a DataContractResolver or add any
types not known statically to the list of known types - for example,
by using the KnownTypeAttribute attribute or by adding them to the
list of known types passed to
DataContractSerializer."} System.Exception
{System.Runtime.Serialization.SerializationException}
这是我的数据对象：
namespace VisuallySpeaking.Data
{
[CollectionDataContract]
public class GrammarList : ObservableCollection<GrammarDataObject>
{
public GrammarList() : base()
{
Add(new GrammarDataObject("My Name", "My name is","Assets/SampleAssets/MyName.png"));
Add(new GrammarDataObject("Where is", "Where is",""));
Add(new GrammarDataObject("Dog", "I have a dog","/Assets/SampleAssets/westie.jpg"));
}
}
[DataContract]
public class GrammarDataObject : VisuallySpeaking.Common.BindableBase
{
private string _Name;
private string _SpeakingText;
private string _ImagePath;
public GrammarDataObject(string Name, string SpeakingText, string ImagePath)
{
this.Name = Name;
this.SpeakingText = SpeakingText;
this.ImagePath = ImagePath;
}
[DataMember]
public string Name
{
get { return _Name; }
set
{
if (this._Name != value)
{
this._Name = value;
this.OnPropertyChanged("Name");
}
}
}
[DataMember]
public string SpeakingText
{
get { return _SpeakingText; }
set
{
if (this._SpeakingText != value)
{
this._SpeakingText = value;
this.OnPropertyChanged("SpeakingText");
}
}
}
[DataMember]
public string ImagePath
{
get { return _ImagePath; }
set
{
if (this._ImagePath != value)
{
this._ImagePath = value;
this.OnPropertyChanged("ImagePath");
}
}
}
}
根据Fresh的评论，我也在这里添加了BindableBase。
namespace VisuallySpeaking.Common
{
/// <summary>
/// Implementation of <see cref="INotifyPropertyChanged"/> to simplify models.
/// </summary>
[Windows.Foundation.Metadata.WebHostHidden]
[DataContract(IsReference = true)]
public abstract class BindableBase : INotifyPropertyChanged
{
/// <summary>
/// Multicast event for property change notifications.
/// </summary>
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// Checks if a property already matches a desired value. Sets the property and
/// notifies listeners only when necessary.
/// </summary>
/// <typeparam name="T">Type of the property.</typeparam>
/// <param name="storage">Reference to a property with both getter and setter.</param>
/// <param name="value">Desired value for the property.</param>
/// <param name="propertyName">Name of the property used to notify listeners. This
/// value is optional and can be provided automatically when invoked from compilers that
/// support CallerMemberName.</param>
/// <returns>True if the value was changed, false if the existing value matched the
/// desired value.</returns>
protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName] String propertyName = null)
{
if (object.Equals(storage, value)) return false;
storage = value;
this.OnPropertyChanged(propertyName);
return true;
}
/// <summary>
/// Notifies listeners that a property value has changed.
/// </summary>
/// <param name="propertyName">Name of the property used to notify listeners. This
/// value is optional and can be provided automatically when invoked from compilers
/// that support <see cref="CallerMemberNameAttribute"/>.</param>
protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var eventHandler = this.PropertyChanged;
if (eventHandler != null)
{
eventHandler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
我假设我不知何故错误地标记了我的GrammarList类，但它让我无法解决。
更新：在错误消息之后(当然(，我添加了KnowTypeAttribute，它似乎有效：
[CollectionDataContract(Name = "GrammarList"),KnownType(typeof(GrammarList))]
public class GrammarList : ObservableCollection<GrammarDataObject>
同样，感谢 Fresh，我用 Name="GrammarList" 更新了 CollectionDataContract，但现在当我从磁盘重新冻结 XML 文件时出现问题。 我收到以下错误消息：
期望来自命名空间的元素"语法列表" "http://schemas.datacontract.org/2004/07/VisuallySpeaking.Data.. 遇到名称为"语法数据对象"的"元素"，命名空间 "http://schemas.datacontract.org/2004/07/VisuallySpeaking.Data"。
序列化的 XML 如下所示：
<?xml version="1.0"?>
<GrammarDataObject xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/VisuallySpeaking.Data" i:type="GrammarList">
<GrammarDataObject xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/" z:Id="i1">
<ImagePath>Assets/SampleAssets/MyName.png</ImagePath>
<Name>My Name</Name>
<SpeakingText>My name is</SpeakingText>
</GrammarDataObject>
<GrammarDataObject xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/" z:Id="i3">
<ImagePath/>
<Name>Where is</Name>
<SpeakingText>Where is</SpeakingText>
</GrammarDataObject>
<GrammarDataObject xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/" z:Id="i4">
<ImagePath>/Assets/SampleAssets/westie.jpg</ImagePath>
<Name>Dog</Name>
<SpeakingText>I have a dog</SpeakingText>
</GrammarDataObject>
</GrammarDataObject>
为什么 XML 外部标记未列为"语法列表"？ 我认为这就是反序列化程序正在寻找的。 当我手动编辑序列化的 xml 以将 GrammarList 作为外部标记时，它会相应地反序列化。 我确信我又错过了什么！
再次更新当我序列化时，我有以下代码：
DataContractSerializer serializer = new DataContractSerializer(typeof(GrammarDataObject));
我将其更改为序列化为语法列表并修复!! 感谢您的帮助新鲜。
DataContractSerializer serializer = new DataContractSerializer(typeof(GrammarList));
查看 XML 输出，看起来集合的名称在反序列化时丢失了。
尝试在 CollectionDataContract 上设置 Name 属性，即
[CollectionDataContract(Name="GrammarList"),KnownType(typeof(GrammarList))]
public class GrammarList : ObservableCollection<GrammarDataObject>