/// <summary>
/// Gets the binding source object of a binding.
/// </summary>
/// <param name="binding">The binding that indicates the source.</param>
/// <param name="serviceProvider">Service provider provided by the framework.</param>
/// <returns>The source object that is described by the binding.</returns>
protected object getBindingSource(Binding binding, IServiceProvider serviceProvider)
{
if (binding == null)
{
return(null);
}
// Optionaly get the target object:
var pvt = serviceProvider?.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget;
var targetObject = pvt?.TargetObject != null ? pvt.TargetObject as DependencyObject : null;
// -- Case where source is explicitely provided: --
if (binding.Source != null)
{
// Get target object as FE if provided:
if (targetObject is FrameworkElement targetAsFE)
{
// And if the binding source is the datacontext of the target object, then add
// the object the to list of datacontexts to be followed:
if (targetAsFE.IsLoaded && targetAsFE.DataContext == binding.Source)
{
if (!DataContextBindings.ContainsKey(binding))
{
DataContextBindings.Add(binding, targetAsFE);
}
return(binding.Source);
}
// Else we cannot know now ,so report assessment when target will be loaded by setting
// the current binding as 'unresolved':
else if (!targetAsFE.IsLoaded)
{
UnresolvedBindings.Add(binding, targetAsFE);
}
}
else
{
return(binding.Source);
}
}
// -- Case where element name is provided, seek source in xaml: --
else if (!string.IsNullOrWhiteSpace(binding.ElementName) && serviceProvider != null)
{
return(BindingHelpers.GetSourceFromElementName(binding.ElementName, serviceProvider));
}
// -- All other case where we have a target to provide: --
else if (targetObject != null)
{
return(getBindingSource(binding, targetObject)); // call the other method without service provider.
}
return(null);
}