/// <summary>
/// Set an attached property value for an instance in the global context.
/// </summary>
/// <typeparam name="TOwner">Type of the instance which the value will be associated
/// with.</typeparam>
/// <typeparam name="TProperty">Type of the attached property value.</typeparam>
/// <param name="instance">The instance to set attached property for.</param>
/// <param name="attachedProperty">The attached property to set a value for.</param>
/// <param name="value"></param>
/// <returns></returns>
public void SetInstanceValue <TOwner, TProperty>(TOwner instance, AttachedProperty <TOwner, TProperty> attachedProperty, TProperty value)
{
if (instance == null)
{
throw new ArgumentNullException(nameof(instance));
}
if (attachedProperty == null)
{
throw new ArgumentNullException(nameof(attachedProperty));
}
EnsureRegistered(attachedProperty);
using (WriteLockScope())
{
var store = _stores.GetOrCreateValue(instance);
if (Equals(value, default(TProperty)))
{
store.RemoveValue(attachedProperty);
if (store.Count == 0)
{
_stores.Remove(instance);
}
}
else
{
store.SetValue(attachedProperty, value);
}
}
}
/// <summary>
/// Get an attached property value from an instance in the global context.
/// </summary>
/// <typeparam name="TOwner">Type of the instance which has the associated attached
/// property value.</typeparam>
/// <typeparam name="TProperty">Type of the attached property value.</typeparam>
/// <param name="instance">The instance to retrieve attached property for.</param>
/// <param name="attachedProperty">The attached property to get a value for.</param>
/// <returns></returns>
public TProperty GetInstanceValue <TOwner, TProperty>(TOwner instance, AttachedProperty <TOwner, TProperty> attachedProperty)
{
if (instance == null)
{
throw new ArgumentNullException(nameof(instance));
}
if (attachedProperty == null)
{
throw new ArgumentNullException(nameof(attachedProperty));
}
EnsureRegistered(attachedProperty);
using (ReadLockScope())
{
var found = _stores.TryGetValue(instance, out var store);
if (!found)
{
return(default(TProperty));
}
found = store.TryGetValue(attachedProperty, out var value);
if (!found)
{
return(default(TProperty));
}
return((TProperty)value);
}
}