如何在运行时更改绑定模式？我可以绑在上面吗？

Question

我需要一种方法在运行时根据某些值将绑定模式从OneWay更改为TwoWay（主要是如果项目是Visible我将使它成为TwoWay，否则OneWay，有点主/从控件）。

这可能来自xaml吗？

提前致谢。

Answer 1

您可以通过以编程方式创建绑定，并在条件更改时重新创建绑定。

Answer 2

我重新绑定了以下内容：

    private void OnTextBoxGotFocus(object sender, RoutedEventArgs e)
    {
        // don't allow to update textbox from source if it has focus
        ChangeBindingMode(sender as TextBox, BindingMode.OneWayToSource);
    }

    private void OnTextBoxLostFocus(object sender, RoutedEventArgs e)
    {
        ChangeBindingMode(sender as TextBox, BindingMode.TwoWay);
    }

    private void ChangeBindingMode(TextBox textbox, BindingMode mode)
    {
        if (textbox == null)
            return;
        Binding oldBinding = BindingOperations.GetBinding(textbox, TextBox.TextProperty);
        // It's not posible to change existing binding, but available to recreate it
        // oldBinding.Mode = mode;
        BindingOperations.ClearBinding(textbox, TextBox.TextProperty);
        Binding newBinding = new Binding(oldBinding.Path.Path);
        newBinding.Mode = mode;
        BindingOperations.SetBinding(textbox, TextBox.TextProperty, newBinding);
    }