validation - Retrieve all Data Bindings from WPF Window

Question

I have a WPF form which has many controls on it. Many (but not all) of these controls are databound to an underlying object. At certain times, such as when the Save button is pressed, I need to check all the validation rules of my controls. Is there a way to do this programatically, WITHOUT hard-coding a list of the controls to be validated? I want this to continue to work after another developer adds another control and another binding, without having to update some list of bindings to be refreshed.

In a nutshell, is there any way to retrieve the collection of all data bindings from a WPF window?

Answer 1

Try out my sample below. I haven't fully tested this so it may have issues. Also, performance may be questionable. Maybe others can help out to make it faster. But anyway, it seems to do the trick.

Note: A limitation to this, however, is that it may not pick up the bindings defined within Styles or DataTemplates. I'm not sure though. Needs more testing.

Anyway, the solution has three parts basically:

1. Use VisualTreeHelper to walk the entire visual tree.
2. For each item in the visual tree, get all dependency properties. Reference.
3. Use BindingOperations.GetBindingBase to get the binding for each property.

GetBindingsRecursive function:

void GetBindingsRecursive(DependencyObject dObj, List<BindingBase> bindingList)
        {
            bindingList.AddRange(DependencyObjectHelper.GetBindingObjects(dObj));

            int childrenCount = VisualTreeHelper.GetChildrenCount(dObj);
            if (childrenCount > 0)
            {
                for (int i = 0; i < childrenCount; i++)
                { 
                    DependencyObject child = VisualTreeHelper.GetChild(dObj, i);
                    GetBindingsRecursive(child, bindingList);
                }
            }
        }

DependencyObjectHelper class:

public static class DependencyObjectHelper
    {
        public static List<BindingBase> GetBindingObjects(Object element)
        {
            List<BindingBase> bindings = new List<BindingBase>();
            List<DependencyProperty> dpList = new List<DependencyProperty>();
            dpList.AddRange(GetDependencyProperties(element));
            dpList.AddRange(GetAttachedProperties(element));

            foreach (DependencyProperty dp in dpList)
            {
                BindingBase b = BindingOperations.GetBindingBase(element as DependencyObject, dp);
                if (b != null)
                {
                    bindings.Add(b);
                }
            }

            return bindings;
        }

        public static List<DependencyProperty> GetDependencyProperties(Object element)
        {
            List<DependencyProperty> properties = new List<DependencyProperty>();
            MarkupObject markupObject = MarkupWriter.GetMarkupObjectFor(element);
            if (markupObject != null)
            {
                foreach (MarkupProperty mp in markupObject.Properties)
                {
                    if (mp.DependencyProperty != null)
                    {
                        properties.Add(mp.DependencyProperty);
                    }
                }
            }

            return properties;
        }

        public static List<DependencyProperty> GetAttachedProperties(Object element)
        {
            List<DependencyProperty> attachedProperties = new List<DependencyProperty>();
            MarkupObject markupObject = MarkupWriter.GetMarkupObjectFor(element);
            if (markupObject != null)
            {
                foreach (MarkupProperty mp in markupObject.Properties)
                {
                    if (mp.IsAttached)
                    {
                        attachedProperties.Add(mp.DependencyProperty);
                    }
                }
            }

            return attachedProperties;
        }
    }

Sample usage:

List<BindingBase> bindingList = new List<BindingBase>();
GetBindingsRecursive(this, bindingList);

foreach (BindingBase b in bindingList)
{
     Console.WriteLine(b.ToString());
}