How to force a WPF binding to refresh?

Question

I have got a combo box with items source attached using simple binding. Is there any way to refresh this binding once combo box is loaded?

Answer 1

You can use binding expressions:

private void ComboBox_Loaded(object sender, RoutedEventArgs e)
{
    ((ComboBox)sender).GetBindingExpression(ComboBox.ItemsSourceProperty)
                      .UpdateTarget();
}

But as Blindmeis noted you can also fire change notifications, further if your collection implements INotifyCollectionChanged (for example implemented in the ObservableCollection<T> ) it will synchronize so you do not need to do any of this.

Answer 2

if you use mvvm and your itemssource is located in your vm. just call INotifyPropertyChanged for your collection property when you want to refresh.

OnPropertyChanged(nameof(YourCollectionProperty));

Answer 3

添加我的 2 美分，如果你想用你的 Control 的新值更新你的数据源，你需要调用UpdateSource()而不是UpdateTarget() ：

((TextBox)sender).GetBindingExpression(TextBox.TextProperty).UpdateSource();

Answer 4

MultiBinding friendly version...

private void ComboBox_Loaded(object sender, RoutedEventArgs e)
{
    BindingOperations.GetBindingExpressionBase((ComboBox)sender, ComboBox.ItemsSourceProperty).UpdateTarget();
}

Answer 5

尝试使用BindingExpression.UpdateTarget()

Answer 6

I was fetching data from backend and updated the screen with just one line of code. It worked. Not sure, why we need to implement Interface. (windows 10, UWP)

    private void populateInCurrentScreen()
    {
        (this.FindName("Dets") as Grid).Visibility = Visibility.Visible;
        this.Bindings.Update();
    }