TextBox, ComboBox, etc binding issues

After update from 3.6.1.236 to 5.0.0.8 a lot of code has been broken Some samples that works perfect on 3.6.1.236 and not work on 5.0.0.8

In this sample binding to Text doesn’t work

<fluent:TextBox SizeDefinition="Small"
                                            Width="40"
                                            Name="FontSizeTextBox"
                                            Text="{Binding Font.Size, Mode=TwoWay}">
                                <i:Interaction.Triggers>
                                    <i:EventTrigger EventName="TextChanged">
                                        <i:InvokeCommandAction Command="{Binding FontSizeCommand}"
                                                               CommandParameter="{Binding Text, ElementName=FontSizeTextBox, Converter={StaticResource StringToIntConverter}}" />
                                    </i:EventTrigger>
                                </i:Interaction.Triggers>
                            </fluent:TextBox>

In this sample binding to SelectedValue doesn’t work

<fluent:ComboBox Name="FontFamilyCombobox"
                                             SizeDefinition="Small"
                                             Width="110"
                                             MaxDropDownHeight="500"
                                             Style="{StaticResource SystemFontCombobox}"
                                             SelectedValuePath="Source"
                                             SelectedValue="{Binding Font.Family, Mode=OneWay}">
                                <i:Interaction.Triggers>
                                    <i:EventTrigger EventName="SelectionChanged">
                                        <i:InvokeCommandAction Command="{Binding FontFamilyCommand}"
                                                               CommandParameter="{Binding ElementName=FontFamilyCombobox, Path=SelectedItem.Source}" />
                                    </i:EventTrigger>
                                </i:Interaction.Triggers>
                            </fluent:ComboBox>

---

Environment

• Fluent.Ribbon v5.0.0.8
• Windows Server 2012R2
• .NET Framework 4.6.1

[batzen]

Ok, now i found out why the behavior changed. In version 3.6 the TextBox in Fluent.Ribbon inherited from RibbonControl and contained a TextBox. Somewhere between that version and version 5.0 the inheritance changed from RibbonControl to TextBox, thus no longer containing a separate TextBox. This change then reveals the bug in System.Windows.Interactivity.

You can use the following code, which is a fixed/modified version of InovkeCommandAction from System.Windows.Interactivity:

public sealed class InvokeCommandActionEx : TriggerAction<DependencyObject>
{
    public static readonly DependencyProperty CommandProperty = DependencyProperty.Register("Command", typeof(ICommand), typeof(InvokeCommandActionEx), (PropertyMetadata)null);
    public static readonly DependencyProperty CommandParameterProperty = DependencyProperty.Register("CommandParameter", typeof(object), typeof(InvokeCommandActionEx), (PropertyMetadata)null);
    private string commandName;

    public string CommandName
    {
        get
        {
            this.ReadPreamble();
            return this.commandName;
        }
        set
        {
            if (!(this.CommandName != value))
                return;
            this.WritePreamble();
            this.commandName = value;
            this.WritePostscript();
        }
    }

    public ICommand Command
    {
        get
        {
            return (ICommand)this.GetValue(InvokeCommandAction.CommandProperty);
        }
        set
        {
            this.SetValue(InvokeCommandAction.CommandProperty, (object)value);
        }
    }

    public object CommandParameter
    {
        get
        {
            return this.GetValue(InvokeCommandAction.CommandParameterProperty);
        }
        set
        {
            this.SetValue(InvokeCommandAction.CommandParameterProperty, value);
        }
    }

    protected override void Invoke(object parameter)
    {
        if (this.AssociatedObject == null)
            return;
        ICommand command = this.ResolveCommand();

        BindingOperations.GetBindingExpression(this.AssociatedObject, InvokeCommandAction.CommandParameterProperty)?.UpdateTarget();

        if (command == null || !command.CanExecute(this.CommandParameter))
            return;
        command.Execute(this.CommandParameter);
    }

    private ICommand ResolveCommand()
    {
        ICommand command = (ICommand)null;
        if (this.Command != null)
            command = this.Command;
        else if (this.AssociatedObject != null)
        {
            foreach (PropertyInfo property in this.AssociatedObject.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public))
            {
                if (typeof(ICommand).IsAssignableFrom(property.PropertyType) && string.Equals(property.Name, this.CommandName, StringComparison.Ordinal))
                    command = (ICommand)property.GetValue((object)this.AssociatedObject, (object[])null);
            }
        }
        return command;
    }
}

The line that solves your issue is:

BindingOperations.GetBindingExpression(this.AssociatedObject, InvokeCommandAction.CommandParameterProperty)?.UpdateTarget();

[User3290]

@punker76 we can’t know about view elements in view model. Generally we don’t speak about MVVM 😃