CODEWITHSUNDEEP
c#wpfxamlserialization
Patrick Pirzer
Patrick Pirzer

Reputation: 1759

How can i serialize a WPF custom control which has a property of type ObservableCollection?

I'm programming a WPF-window-designer application. In the designer i can add customcontrols to the window and save the window by serializing the Canvas panel on which the added customcontrols are lying to XAML.

public string SerializeControlToXaml(FrameworkElement control)
{
    StringBuilder outstr = new StringBuilder();

    XmlWriterSettings settings = new XmlWriterSettings();
    settings.Indent = true;
    settings.OmitXmlDeclaration = true;
    XamlDesignerSerializationManager dsm =
            new XamlDesignerSerializationManager(XmlWriter.Create(outstr, settings));
    dsm.XamlWriterMode = XamlWriterMode.Expression;
    System.Windows.Markup.XamlWriter.Save(control, dsm);

    string xaml = outstr.ToString();
    return xaml;
}

After that serialization i get the xaml as string and save it in a file which i can reload later.

Now my problem is that i added a new dependency property to one of my customcontrols which is of type ObservableCollection. Each time i have set that property and try to serialize the canvas to XAML i get an error message:

"Invalid initials in 'ObservableCollection 1'. The sign '', hexadecimal value 0x60, may not be contained in a name."

I never give the collection a name. What's going wrong?

This is the viewmodel-property to which i bind the control:

public ObservableCollection<string> SelectedFormulas
{
    get
    {
        return selectedFormulas;
    }
    set
    {
        selectedFormulas = value;
        RaisePropertyChanged("SelectedFormulas");
    }
}

And this is my dependencyproperty:

public static readonly DependencyProperty SelectedFormulasProperty =
        DependencyProperty.Register("SelectedFormulas", typeof(ObservableCollection<string>), typeof(CustomNumericField));

public ObservableCollection<string> SelectedFormulas
{
    get { return GetValue(SelectedFormulasProperty) as ObservableCollection<string>; }
    set { SetValue(SelectedFormulasProperty, value); }
}

Upvotes: 1

Views: 1236

Answers (1)

Patrick Pirzer
Patrick Pirzer

Reputation: 1759

The answer from dbc is the solution.

What i needed was a non-generic class instead of the ObservableCollection.

This is the new class:

public class SelectedFormulaCollection : ObservableCollection<string>
{
}

And here the DependencyProperty in the customcontrol (Type of the property in the viewmodel must be changed too!):

    public static readonly DependencyProperty SelectedFormulasProperty =
        DependencyProperty.Register("SelectedFormulas", typeof(SelectedFormulaCollection), typeof(CustomNumericField));

    public SelectedFormulaCollection SelectedFormulas
    {
        get { return GetValue(SelectedFormulasProperty) as SelectedFormulaCollection; }
        set { SetValue(SelectedFormulasProperty, value); }
    }

Upvotes: 3

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