Question

我在Adorner中创建了一个名为OpacityAdorner的滑块控件，用于控制它所属控件的不透明度。我在http://www.codeproject.com/Articles/22952/WPF-Diagram-Designer-Part处遵循了Adorner示例，该示例使用xaml样式来帮助形成装饰，这可能会增加一些复杂性。目前，我可以找到将滑块的ValueChange挂钩到ViewModel的唯一方法，看起来有点hacky，我更喜欢有绑定。我不能完全理解这一点：

protected override void OnInitialized( System.EventArgs e )
    {
        base.OnInitialized( e );

        if( m_chrome != null && m_chrome.Template != null && m_slider == null )
        {
            m_chrome.ApplyTemplate();
            m_slider = m_chrome.Template.FindName( "OpacitySlider", m_chrome ) as Slider;
            if( m_slider != null )
            {
                m_slider.ValueChanged += opacity_value_changed;
                //Binding opacityBinding = new Binding( "OpacityValue" );
                //Control ctrl = (Control)m_chrome.DataContext;
                //SettingsViewModel settingsVM = ctrl.DataContext as SettingsViewModel;
                //opacityBinding.Source = settingsVM;
                //////opacityBinding.Path = new PropertyPath( "OpacitySlider" );
                //m_slider.SetBinding( SettingsViewModel.OpacticyProperty, opacityBinding );
            }
            m_opacity_button = m_chrome.Template.FindName( "OpacitySliderEnable", m_chrome ) as Ellipse;
            if( m_opacity_button != null )
            {
                m_opacity_button.PreviewMouseLeftButtonDown += m_opacity_button_MouseLeftButtonDown;
            }
        }           
    }

和

void opacity_value_changed( object sender, RoutedPropertyChangedEventArgs<double> e )
    {
        Control ctrl = (Control)m_chrome.DataContext;
        SettingsViewModel settingsVM = ctrl.DataContext as SettingsViewModel;
        settingsVM.OpacityValue = e.NewValue;
    }

理想情况下，我只是希望在已注释掉的部分中使用绑定，删除opacity_value_changed事件。我还想知道是否有更简洁的方法来检索SettingsViewModel，而不先获取容器chrome控件，然后从它的DataContext中获取视图模型？

从Adorner绑定到基础ViewModel

0 个答案: