Question

I am developing a WPF project and right now I am working on the Ribbon area.

Inside of the Ribbon I have some controls such as RibbonComboBox, RibbonTextBox, etc.

I have several RibbonTab in my Ribbon so I set one view model for each RibbonTab as following:

<rb:Ribbon Name="Ribbon">

        <rb:RibbonTab Header="Tab One" Name="tab1">

            <rb:RibbonTab.DataContext>
                <vm:TabOneViewModel />
            </rb:RibbonTab.DataContext>

So, each control within those tabs inherits their respective view model.

When I run the application everything works as expected. The problem starts when I resize the container window to a very small size, after doing this: Every control loses their bindings since their DataContext is replaced by an object called DisconnectedItem.

I have done some research and found that this is due to the controls stop being part of the visual tree and for that reason the binding engine sets their DataContext to DisconnectedItem.

What can I do to prevent my controls from losing their DataContext?

EDIT:

I just found that the main problem comes from the RibbonGroup control which after collapsing causes its visual children lose their DataContext.

Answer 1

I just found a workaround for the RibbonGroup control issue here

The solution I took is creating a new control which inherits from RibbonGroup control.

    public class MyRibbonGroup : RibbonGroup
    {
    public MyRibbonGroup() 
        : base()
    {
    }

    protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
    {
        base.OnPropertyChanged(e);

        // Force the bindings to be restored after 
        // the ribbon group collapsed or expanded to a menu button.
        if (e.Property == RibbonGroup.IsCollapsedProperty)
        {
            object objDataContext = this.DataContext;
            this.DataContext = null;
            this.DataContext = objDataContext;
        }
    }
}