WPF. Find control that binds to specific property - wpf

Question

Any ideas on how to implement a method that given a propertyname, finds a control (perhaps from a visualtree) which is bound to the given property?

Answer 1

Try this one. First, copy-paste this DependencyObjectHelper class in your project. It has a function that allows you to get all the BindingObjects in a given object.
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(DependencyObjectHelper.GetDependencyProperties(element));
dpList.AddRange(DependencyObjectHelper.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;
}
}
Then, create this GetBindingSourcesRecursive function. It recursively collects the DependencyObjects in the visual tree that has at least one Binding object targetting a given property name.
private void GetBindingSourcesRecursive(string propertyName, DependencyObject root, List<object> sources)
{
List<BindingBase> bindings = DependencyObjectHelper.GetBindingObjects(root);
Predicate<Binding> condition =
(b) =>
{
return (b.Path is PropertyPath)
&& (((PropertyPath)b.Path).Path == propertyName)
&& (!sources.Contains(root));
};
foreach (BindingBase bindingBase in bindings)
{
if (bindingBase is Binding)
{
if (condition(bindingBase as Binding))
sources.Add(root);
}
else if (bindingBase is MultiBinding)
{
MultiBinding mb = bindingBase as MultiBinding;
foreach (Binding b in mb.Bindings)
{
if (condition(bindingBase as Binding))
sources.Add(root);
}
}
else if (bindingBase is PriorityBinding)
{
PriorityBinding pb = bindingBase as PriorityBinding;
foreach (Binding b in pb.Bindings)
{
if (condition(bindingBase as Binding))
sources.Add(root);
}
}
}
int childrenCount = VisualTreeHelper.GetChildrenCount(root);
if (childrenCount > 0)
{
for (int i = 0; i < childrenCount; i++)
{
DependencyObject child = VisualTreeHelper.GetChild(root, i);
GetBindingSourcesRecursive(propertyName, child, sources);
}
}
}
Then, to use this, just call GetBindingsRecursive passing in the property name, the root visual (e.g. the Window), and an object list that will contain the results.
List<object> sources = new List<object>();
GetBindingSourcesRecursive("SomePropertyPath", this, sources);
sources.ForEach((o) => Console.WriteLine(o.ToString()));
Hope this helps.

Answer 2

I created code based on accepted ASanch answer. This code uses LogicalTreeHelper which makes it 6times faster (130ms vs 20ms when looking for control with specific binding on simple window).
Plus I fix some errors in ASanch code (look at original "else if (bindingBase is MultiBinding)" or "else if (bindingBase is PriorityBinding)").
public static class DependencyObjectHelper
{
/// <summary>
/// Gets all dependency objects which has binding to specific property
/// </summary>
/// <param name="dependencyObject"></param>
/// <param name="propertyName"></param>
/// <returns></returns>
public static IList<DependencyObject> GetDependencyObjectsWithBindingToProperty(DependencyObject dependencyObject, string propertyName)
{
var list = new List<DependencyObject>();
GetDependencyObjectsWithBindingToPropertyRecursive(propertyName, dependencyObject, list);
return list;
}
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
/// <param name="dependencyObject"></param>
/// <param name="sources"></param>
/// <remarks>
/// Based on ASanch answer on http://stackoverflow.com/questions/3959421/wpf-find-control-that-binds-to-specific-property
/// </remarks>>
private static void GetDependencyObjectsWithBindingToPropertyRecursive(string propertyName, DependencyObject dependencyObject, ICollection<DependencyObject> sources)
{
var dependencyProperties = new List<DependencyProperty>();
dependencyProperties.AddRange(MarkupWriter.GetMarkupObjectFor(dependencyObject).Properties.Where(x => x.DependencyProperty != null).Select(x => x.DependencyProperty).ToList());
dependencyProperties.AddRange(
MarkupWriter.GetMarkupObjectFor(dependencyObject).Properties.Where(x => x.IsAttached && x.DependencyProperty != null).Select(x => x.DependencyProperty).ToList());
var bindings = dependencyProperties.Select(x => BindingOperations.GetBindingBase(dependencyObject, x)).Where(x => x != null).ToList();
Predicate<Binding> condition = binding => binding != null && binding.Path.Path == propertyName && !sources.Contains(dependencyObject);
foreach (var bindingBase in bindings)
{
if (bindingBase is Binding)
{
if (condition(bindingBase as Binding))
sources.Add(dependencyObject);
}
else if (bindingBase is MultiBinding)
{
if (((MultiBinding)bindingBase).Bindings.Any(bindingBase2 => condition(bindingBase2 as Binding)))
{
sources.Add(dependencyObject);
}
}
else if (bindingBase is PriorityBinding)
{
if (((PriorityBinding)bindingBase).Bindings.Any(bindingBase2 => condition(bindingBase2 as Binding)))
{
sources.Add(dependencyObject);
}
}
}
var children = LogicalTreeHelper.GetChildren(dependencyObject).OfType<DependencyObject>().ToList();
if (children.Count == 0)
return;
foreach(var child in children)
{
GetDependencyObjectsWithBindingToPropertyRecursive(propertyName, child, sources);
}
}
}