DataContractSerializer 序列化 List出现错误

Question

我目前正在尝试序列化一个列表，它序列化（我认为很好），但是当它反序列化时，

抱歉代码量很大，但我真的被困住了，不知道为什么会发生这种情况，我也尝试更改结构进入班级却没有任何帮助。

谢谢。

我收到以下错误更新

    There was an error deserializing the object of type There was an error deserializing the object of type 
`System.Collections.Generic.List`1[[A.B.C.DataValues, A.V, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]. Unexpected end of file. Following elements are not closed: Time, DataValues, ArrayOfDataValues.`

我像这样序列化更新

     public void SerializeDataValue(List<DataValues> values)
            {
                DataContractSerializer serializer = new DataContractSerializer(typeof(List<DataValues>));

                using (MemoryStream stream = new MemoryStream())
                {
                    using (GZipStream compress = new GZipStream(stream, CompressionMode.Compress))
                    {
                        XmlDictionaryWriter w = XmlDictionaryWriter.CreateBinaryWriter(compress);
                        serializer.WriteObject(w, values);

                    }
                    _serializedData = stream.ToArray();
                }
            }

我像这样反序列化更新

 public List<DataValues> DeserializeDataValue()
{
    if (SerializedData == null || SerializedData.Length == 0)
    {
        return new List<DataValues> ();
    }
    else
    {
        DataContractSerializer serializer = new DataContractSerializer(typeof(List<DataValues>));
        using (MemoryStream stream = new MemoryStream(SerializedData))
        {
            using (GZipStream decompress = new GZipStream(stream, CompressionMode.Decompress))
            {
                XmlDictionaryReader r = XmlDictionaryReader.CreateBinaryReader(decompress, XmlDictionaryReaderQuotas.Max);
                return serializer.ReadObject(r, true) as List<DataValues>;
            }
        }
    }
}

属性

private byte[] _serializedData;

[DataMember]
[Browsable(false)]
public byte[] SerializedData
{
    get { return _serializedData; }
    set { _serializedData = value; }
}

助手方法

public static byte[] ReadFully(Stream input)
{
    byte[] buffer = new byte[16 * 1024];
    input.Position = 0;
    using (MemoryStream ms = new MemoryStream())
    {
        int read;
        while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
        {
            ms.Write(buffer, 0, read);
        }
        return ms.ToArray();
    }
}

结构

[DataContract(Name = "DataValues", Namespace = "A.B.C")]
public struct DataValues
{
    [DataMember]
    public DateTime Time { get; set; }
    [DataMember]
    public Single Value { get; set; }

    public DataValues(DateTime dateTime, Single value)
    {
        Time = dateTime;
        Value = value;
   }
} 

Answer 1

这是因为您没有完全序列化对象。写入后需要关闭流，尤其是在使用 gzip 时。推荐的做法是使用 using：

public void SerializeDataValue(List<DataValues> values)
{
    DataContractSerializer serializer = new DataContractSerializer(typeof(List<DataValues>));
    using (MemoryStream stream = new MemoryStream())
    {
        using (GZipStream compress = new GZipStream(stream, CompressionMode.Compress))
        {
            XmlDictionaryWriter w = XmlDictionaryWriter.CreateBinaryWriter(compress);
            serializer.WriteObject(w, values);
        }
        _serializedData = stream.ToArray();
    }
}

Answer 2

抱歉迟到了这个问题。

最初方法的问题很简单，就是您没有刷新（阅读：处置）XmlDictionaryWriter。

这应该有效（注意第二个 using 子句）：

using (GZipStream compress = new GZipStream(stream, CompressionMode.Compress))
using (XmlDictionaryWriter w = XmlDictionaryWriter.CreateBinaryWriter(compress))
{
    serializer.WriteObject(w, values);
}

希望这对某人有帮助。

Answer 3

我可以通过删除 XmlDictionaryReader 并直接将输入/输出流输入 DataContractSerializer 来使示例正常工作。对于大型压缩集合，这可能是 XmlDictionaryReader 中的缺陷，但我不确定。

希望这有帮助：

public void SerializeDataValue(List<DataValues> values)
            {
                DataContractSerializer serializer = new DataContractSerializer(typeof(List<DataValues>));
                    using (MemoryStream stream = new MemoryStream())
                {
                    using (GZipStream compress = new GZipStream(stream, CompressionMode.Compress))
                    {
                        serializer.WriteObject(compress , values);

                    }
                    _serializedData = stream.ToArray();
                }
            }

    public List<DataValues> DeserializeDataValue()
    {
        if (SerializedData == null || SerializedData.Length == 0)
        {
            return new List<DataValues> ();
        }
        else
        {
            DataContractSerializer serializer = new DataContractSerializer(typeof(List<DataValues>));
            using (MemoryStream stream = new MemoryStream(SerializedData))
            {
                using (GZipStream decompress = new GZipStream(stream, CompressionMode.Decompress))
                {
                    return serializer.ReadObject(decompress , true) as List<DataValues>;
                }
            }
        }
    }

Answer 4

我遇到了完全相同的问题，我终于找到了解决方案：需要在您写入的流本身关闭之前释放/关闭 XmlDictionaryWriter。我发现这要归功于 http://www.albahari.com/nutshell/ch15 中找到的完整示例.aspx 比 MSDN 更完整。

在您的示例代码中，这将是：

            using (XmlDictionaryWriter w = XmlDictionaryWriter.CreateBinaryWriter(compress))
            {
                serializer.WriteObject(w, values);
            }

在我自己的示例中，使用 XmlDictionaryWriter 而不是普通的默认 Xml writer 仅使文件大小减少了约 25%，但在读回对象时减少了 3 倍。