序列化自定义集合时遇到问题

Question

I have a DataGrid which holds configuration parameters for a robot I am working on. I am trying to add the functionality to import/export sets of parameters, and I am trying to do so with XML Serialization.

I am a complete novice to XML Serialization, and still pretty new to C#, so I have no idea where I am going wrong.

I made a class, shown below, to hold the values from the data grid. I could not use the same type which populates the datagrid, as there is so much disconnected logic and garbage in that class that serialization will never work.

[Serializable]
public class CmcdSerializationBuffer
{
    [XmlElement]
    public string Name { get; set; }

    [XmlElement]
    public string TypeAssemblyQualifiedName { get; set; }

    private string _storedValue;
    [XmlElement]
    public string StoredValue
    {
        get { return _storedValue; }
        set { _storedValue = value; }
    }

    private string _temporaryValueFromUser;
    public string TemporaryValueFromUser
    {
        get { return _temporaryValueFromUser; }
        set { _temporaryValueFromUser = value; }
    }

    [XmlElement]
    public string DefaultValue { get; set; }

    public CmcdSerializationBuffer()
    {

    }

    public CmcdSerializationBuffer(CmcdConfigurationParameter parameter)
    {
        Name = parameter.Name;
        TypeAssemblyQualifiedName = parameter.TypeAssemblyQualifiedName;
        StoredValue = parameter.StoredValue;
        TemporaryValueFromUser = parameter.TemporaryValueFromUser;
        DefaultValue = parameter.DefaultValue;
    }

}

So I made this class to bypass that, it just takes in a CmcdConfigurationParameter (The type populating the DataGrid) and copies the values.

This, by the way, serializes properly.

I want to export multiple of these into a single file, so I figured I would make a custom collection class that holds CmcdSerializatinonBuffer objects. Here is what I have:

[Serializable]
public class ValuesToExport
{
    [XmlArray("ParamsList")]
    public List<CmcdSerializationBuffer> Parameters { get; set; }

    public ValuesToExport()
    {
        Parameters = new List<CmcdSerializationBuffer>();
    }

    public ValuesToExport(List<CmcdSerializationBuffer> parameters)
    {
        Parameters = new List<CmcdSerializationBuffer>();
        Parameters = parameters;
    }
}

And here is the function I use to export the values:

public void Export()
    {
        ValuesToExport val = new ValuesToExport();
        CmcdSerializationBuffer tempBuffer = new CmcdSerializationBuffer();
        foreach (CmcdConfigurationParameter param in MasterDataGrid.ItemsSource)
        {

            tempBuffer = new CmcdSerializationBuffer(param);
            val.Parameters.Add(tempBuffer);
            Console.WriteLine(val.Parameters.Count());
        }


        MessageBox.Show(MasterDataGrid.ItemsSource.GetType().ToString());
        //ValuesToExport val = new ValuesToExport(MasterDataGrid.ItemsSource);

        XmlSerializer serialiser = new XmlSerializer(typeof(ValuesToExport));

        using (FileStream fs = new FileStream("D:\\test\\testserialization.txt", FileMode.OpenOrCreate))
        using (TextWriter writer = new StreamWriter(fs))
        {
            serialiser.Serialize(writer, val.Parameters);
            Console.WriteLine(val.Parameters);
            writer.Close();
        }
    }

I don't know if that is the right way to do it, but it works for a single parameter. However, when I try to serialize my ValuesToExport class I get an error saying:

"Unable to cast object of type 'System.Collections.Generic.List`1[Hamilton.HST.MotionController.DeviceConfiguration.CmcdSerializationBuffer]' to type 'Hamilton.HST.MotionController.DeviceUI.ValuesToExport'."

And I have not been able to fix this. If anyone knows how I can fix this, I would love to know. Thanks!

Answer 1

You're getting this error because you created an XmlSerializer for the type ValuesToExport , but when you call the .Serialize method, you're passing it a list of CmcdSerializationBuffer . It's not the type the serializer was expecting, so it throws the error.

To fix it, you can change this line:

serialiser.Serialize(writer, val.Parameters);

to this:

serialiser.Serialize(writer, val);