How to hide a part of a WPF control

Question

Is it possible to hide a part of a WPF control? .NET 4 has a DatePicker which renders 4 parts, according to MSDN. Is it possible to hide (in my case) the TextBox part (probably

Answer 1

You can do it all in XAML with behaviors and the TemplatePartAction I wrote:

and here is the TemplatePart functionality:

public class TemplatePartHelper where T : IAttachedObject
{
    public IAttachedObject Parent { get; set; }
    public List Children { get; private set; }
    public string Name { get; set; }
    public Control TemplatePart { get; set; }

    public TemplatePartHelper(IAttachedObject parent)
    {
        Parent = parent;
        Children = new List();
    }

    public void AssociateChildren()
    {
        if (TemplatePart != null)
            return;
        var control = Parent.AssociatedObject as Control;
        var template = control.Template;
        if (template == null)
            return;
        var partName = "PART_" + Name;
        TemplatePart = template.FindName(partName, control) as Control;
        if (TemplatePart == null)
            return;
        foreach (var child in Children)
            child.Attach(TemplatePart);
    }
}

[ContentProperty("Behaviors")]
public class TemplatePartBehavior : Behavior
{
    public TemplatePartHelper Helper { get; private set; }
    public List Behaviors { get { return Helper.Children; } }
    public string TemplatePartName { get { return Helper.Name; } set { Helper.Name = value; } }

    public TemplatePartBehavior()
    {
        Helper = new TemplatePartHelper(this);
    }

    protected override void OnAttached()
    {
        AssociatedObject.Initialized += (s, e) => Helper.AssociateChildren();
        AssociatedObject.Loaded += (s, e) => Helper.AssociateChildren();
    }
}

[ContentProperty("Actions")]
public class TemplatePartAction : TriggerAction
{
    public TemplatePartHelper Helper { get; private set; }
    public List Actions { get { return Helper.Children; } }
    public string TemplatePartName { get { return Helper.Name; } set { Helper.Name = value; } }

    public TemplatePartAction()
    {
        Helper = new TemplatePartHelper(this);
    }

    protected override void OnAttached()
    {
        AssociatedObject.Loaded += (s, e) => Helper.AssociateChildren();
    }

    protected override void Invoke(object parameter)
    {
        foreach (var action in Actions)
        {
            if (action.IsEnabled)
            {
                var methodInfo = typeof(TriggerAction).GetMethod("Invoke", BindingFlags.Instance | BindingFlags.NonPublic, null, new Type[] { typeof(object) }, null);
                methodInfo.Invoke(action, new object[] { parameter });
            }
        }
    }
}

If you are not familiar with behaviors, Install the Expression Blend 4 SDK and add these namespaces:

xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"

and add System.Windows.Interactivity and Microsoft.Expression.Interactions to your project.