WPF - Getting a property value from a binding path

Question

if I have an object say called MyObject, which has a property called MyChild, which itself has a property called Name. How can I get the value of that Name property if all I have is a binding path (i.e. "MyChild.Name"), and a reference to MyObject?

MyObject
  -MyChild
    -Name

Answer 1

I am doing it this way. Please let me know if this is a terrible idea, as C# is just a side job for me so I am not an expert objectToAddTo is of type ItemsControl:

BindingExpression itemsSourceExpression = GetaBindingExression(objectToAddTo);
object itemsSourceObject = (object)itemsSourceExpression.ResolvedSource;
string itemSourceProperty = itemsSourceExpression.ResolvedSourcePropertyName;

object propertyValue = itemsSourceObject.GetType().GetProperty(itemSourceProperty).GetGetMethod().Invoke(itemsSourceObject, null); // Get the value of the property

Answer 2

I found a way to do this, but it's quite ugly and probably not very fast... Basically, the idea is to create a binding with the given path and apply it to a property of a dependency object. That way, the binding does all the work of retrieving the value:

public static class PropertyPathHelper
{
    public static object GetValue(object obj, string propertyPath)
    {
        Binding binding = new Binding(propertyPath);
        binding.Mode = BindingMode.OneTime;
        binding.Source = obj;
        BindingOperations.SetBinding(_dummy, Dummy.ValueProperty, binding);
        return _dummy.GetValue(Dummy.ValueProperty);
    }

    private static readonly Dummy _dummy = new Dummy();

    private class Dummy : DependencyObject
    {
        public static readonly DependencyProperty ValueProperty =
            DependencyProperty.Register("Value", typeof(object), typeof(Dummy), new UIPropertyMetadata(null));
    }
}

Answer 3

I developed a nuget package Pather.CSharp that does exactly what you need.

It contains a class Resolver that has a Resolve method which behaves like @ThomasLevesque's GetValue method.
Example:

IResolver resolver = new Resolver(); 
var o = new { Property1 = Property2 = "value" } }; 
var path = "Property1.Property2";    
object result = r.Resolve(o, path); //the result is the string "value"

It even supports collection access via index or dictionary access via key.
Example paths for these are:

"ArrayProperty[5]"
"DictionaryProperty[Key]"

Answer 4

not sure what you want to do but and how (xaml or code) yet you can always name your object

<MyObject x:Name="myBindingObject" ... />

an then use it in code

myBindingObject.Something.Name

or in xaml

<BeginStoryboard>
 <Storyboard>
    <DoubleAnimation
        Storyboard.TargetName="myBindingObject"
        Storyboard.TargetProperty="Background"
        To="AA2343434" Duration="0:0:2" >
    </DoubleAnimation>
 </Storyboard>
</BeginStoryboard>