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我有結合了2個DepedenciyProperties的值的用戶控制內:WPF訪問的DependencyObject一個CollectionChanged事件
INT numberPeople和成分列出<>
我想在這些值的更新以重做組合。 我目前的實現使用一個靜態變量來跟蹤對象實例(objectInstance)。我想知道是否有更乾淨的方法來做到這一點。
private static DependencyObject objectInstance;
public int numberPeople
{
get { return (int)GetValue(numberPeopleProperty); }
set { SetValue(numberPeopleProperty, value); }
}
public static readonly DependencyProperty numberPeopleProperty =
DependencyProperty.Register("numberPeople", typeof(int), typeof(ListDisplayer), new PropertyMetadata(0, Combine));
public ObservableCollection<ListModel> ingredients
{
get { return (ObservableCollection<ListModel>)GetValue(ingredientsProperty); }
set { SetValue(ingredientsProperty, value); }
}
public static readonly DependencyProperty ingredientsProperty =
DependencyProperty.Register("ingredients", typeof(ObservableCollection<ListModel>), typeof(ListDisplayer), new PropertyMetadata(null, AssignCollectionChangedToList));
private static void AssignCollectionChangedToList(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var instance = d as ListDisplayer;
if (e.OldValue != null)
{
var coll = (INotifyCollectionChanged)e.OldValue;
coll.CollectionChanged -= ItemsSource_CollectionChanged;
}
if (e.NewValue != null)
{
instance.ItemsSource = (ObservableCollection<ListModel>)e.NewValue;
objectInstance = instance;
instance.ItemsSource.CollectionChanged += ItemsSource_CollectionChanged;
}
}
private static void ItemsSource_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
// MY PROBLEM: when a new item is added in this list trigger again Combine(), is there
// another way to trigger the Combine so that it will process the IngredientList and numberPeople attached to the object ?
Combine(objectInstance, new DependencyPropertyChangedEventArgs());
}
private static void Combine(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
// process numberPeople and ingredientList
}
更新了代碼以及代碼中的註釋。註釋現在位於方法ItemsSource_CollectionChanged中。希望我已經設法很好地解釋我這個問題是什麼。 –