protected virtual void OnPropertyChanged(
DependencyProperty dp, object oldValue, object newValue)
{
if (PropertyChanged != null)
PropertyChanged(
this, new DependencyPropertyChangedEventArgs(dp, oldValue, newValue));
}
public object GetValue(DependencyProperty property)
{
if (properties != null
&& properties.ContainsKey(property))
return properties[property];
if (property.DefaultMetadata != null
&& property.DefaultMetadata.DefaultValue != null)
return property.DefaultMetadata.DefaultValue;
return GetDefaultValueOfType (property.PropertyType);
}
public static DependencyProperty RegisterAttached(string name, Type propertyType, Type ownerType, PropertyMetadata metadata)
{
var prop = new DependencyProperty(name, propertyType, ownerType, metadata);
attachedProperties.Add(prop);
return prop;
}
/// <summary>
/// Eigenschaft als gesetzt markieren
/// </summary>
/// <param name="property">Property.</param>
protected void SetPropertyAsAssigned(DependencyProperty property)
{
if (propertySet == null)
{
#if WINDOWS_PHONE
propertySet = new List<DependencyProperty>();
#else
propertySet = new HashSet<DependencyProperty>();
#endif
}
if (!propertySet.Contains(property))
propertySet.Add(property);
}
protected virtual void OnPropertyChanging(
DependencyProperty dp, object oldValue, object newValue)
{
}
/// <summary>
/// Gibt true zurück, wenn die zugehörige DependencyProperty vor dem initialisieren zugewiesen wurde,
/// - Wenn zugewiesen, kann die DependencyProperty nicht mehr über einen Style verändert werden.
/// </summary>
internal bool IsAssignedProperty(DependencyProperty dp)
{
return propertySet != null && propertySet.Contains(dp);
}
public void SetValue(DependencyProperty property, object value)
{
SetValue(property, value, true);
}
protected void SetValue(DependencyProperty property, object value, bool setAsAssigned)
{
if (properties == null)
properties = new Dictionary<DependencyProperty, object>();
// Zieltyp prüfen
if (value != null && !property.PropertyType.IsAssignableFrom(value.GetType()))
throw new InvalidCastException();
var oldValue = properties.ContainsKey(property) ? properties[property] : null;
if ((oldValue == null && value != null)
|| (oldValue != null && value == null)
|| (oldValue != null && value != null && !oldValue.Equals(value)))
{
OnPropertyChanging(property, oldValue, value);
properties[property] = value;
OnPropertyChanged(property, oldValue, value);
if (setAsAssigned)
{
// Eigenschaft als gesetzt markieren,
// AssignedProperties können nicht mehr vom Style überschrieben werden
SetPropertyAsAssigned(property);
}
// TODO DefaultValue Metadata...
if (property.DefaultMetadata != null
&& property.DefaultMetadata.PropertyChangedCallback != null)
property.DefaultMetadata.PropertyChangedCallback(
this, new DependencyPropertyChangedEventArgs(
property, oldValue, value));
}
}
