Set multi-connectivity for xaml element in code

Question

I have the following working XAML code that basically binds a couple of properties to calculate the end position of my user control:

<UserControl x:Class="CurvePointControl"
    ....
         >
<UserControl.Resources>
    <local:VToYConverter x:Key="vToYConverter" />
</UserControl.Resources>
<UserControl.RenderTransform>
    <TranslateTransform x:Name="XTranslateTransform" >
        <TranslateTransform.Y>
            <MultiBinding Converter="{StaticResource vToYConverter}">
                <Binding ElementName="curveEditPoint" Path="V"/>
                <Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type local:CurveEditor}}" Path="MinV"/>
                <Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type local:CurveEditor}}" Path="MaxV"/>
                <Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type local:CurveEditor}}" Path="ActualHeight"/>                    
            </MultiBinding>
        </TranslateTransform.Y>
    </TranslateTransform>
</UserControl.RenderTransform>

...

For various reasons (but esp, to avoid a relative source, I am now trying to do the same in code without success.

This is my current code:

    public CurvePointControl(CurveEditor CV)
    {
        InitializeComponent();

        MultiBinding multiBinding = new MultiBinding();
        multiBinding.Converter = m_VToYConverter;

        multiBinding.Bindings.Add(new Binding("V"));
        multiBinding.Bindings.Add(new Binding(CV.MinVProperty)); // doesn't work
        multiBinding.Bindings.Add(new Binding(CV.MaxVProperty)); // doesn't work
        multiBinding.Bindings.Add(new Binding(CV.ActualHeight)); // doesn't work       
        multiBinding.NotifyOnSourceUpdated= true;

        this.SetBinding(TranslateTransform.YProperty, multiBinding);
        //Doesn't work too:
        //BindingOperations.SetBinding(XTranslateTransform, TranslateTransform.YProperty, multiBinding);

    }

I still can't believe it is so hard to convert XAML to C # code. The converter is invoked, but only once and without valid property values.

Any idea what is wrong? How could I debug such a problem?

Answer 1

You need sources:

multiBinding.Bindings.Add(new Binding("V") { Source = curveEditPoint }); //If that object is accessible in the current scope.
multiBinding.Bindings.Add(new Binding("MinV") { Source = CV });
multiBinding.Bindings.Add(new Binding("MaxV") { Source = CV });
multiBinding.Bindings.Add(new Binding("ActualHeight") { Source = CV });

Answer 2

:

MultiBinding multiBinding = new MultiBinding();
multiBinding.Converter = m_VToYConverter;

RelativeSource relativeSource = new RelativeSource() { AncestorType = typeof(CurveEditor) };

multiBinding.Bindings.Add(new Binding("V") { ElementName = "curveEditPoint" });
multiBinding.Bindings.Add(new Binding(CV.MinVProperty) { RelativeSource = relativeSource });
multiBinding.Bindings.Add(new Binding(CV.MaxVProperty) { RelativeSource = relativeSource });
multiBinding.Bindings.Add(new Binding(CV.ActualHeight) { RelativeSource = relativeSource });

ElementName. "" . - , curveEditPoint :

multiBinding.Bindings.Add(new Binding("V") { Source = this.curveEditPoint });

Answer 3

Try using

multiBinding.Bindings.Add(new Binding("MinVProperty") { ElementName = CV.Name });

instead

multiBinding.Bindings.Add(new Binding("CV.MinVProperty"));