WPF 获取绑定的事件处理程序绑定全局资源

1. 我们想要获取绑定到 button 上面的所有 click event handler actions. 可以使用以下的代码.

namespace RoutedEventHandlerInfoTest
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.Loaded += MainWindow_Loaded;
        }

        void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            this.btnTest.Click+=btnTest_Click;
            var infos = GetRoutedEventHandlers(this.btnTest, ButtonBase.ClickEvent);
        }

        private void btnTest_Click(object sender, RoutedEventArgs e)
        {
            Console.WriteLine(" button clicked");
        }

        /// <summary>
        /// Gets the list of routed event handlers subscribed to the specified routed event.
        /// </summary>
        /// <param name="element">The UI element on which the event is defined.</param>
        /// <param name="routedEvent">The routed event for which to retrieve the event handlers.</param>
        /// <returns>The list of subscribed routed event handlers.</returns>
        public static RoutedEventHandlerInfo[] GetRoutedEventHandlers(UIElement element, RoutedEvent routedEvent)
        {
            // Get the EventHandlersStore instance which holds event handlers for the specified element.
            // The EventHandlersStore class is declared as internal.
            var eventHandlersStoreProperty = typeof(UIElement).GetProperty(
                "EventHandlersStore", BindingFlags.Instance | BindingFlags.NonPublic);
            object eventHandlersStore = eventHandlersStoreProperty.GetValue(element, null);

            // Invoke the GetRoutedEventHandlers method on the EventHandlersStore instance 
            // for getting an array of the subscribed event handlers.
            var getRoutedEventHandlers = eventHandlersStore.GetType().GetMethod(
                "GetRoutedEventHandlers", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
            var routedEventHandlers = (RoutedEventHandlerInfo[])getRoutedEventHandlers.Invoke(
                eventHandlersStore, new object[] { routedEvent });

            return routedEventHandlers;
        }
    }
}

分析下代码:　关键在　GetRoutedEventHandlers(UIElement, RoutedEvent) 方法. 这个方法首先从 UIElement 中获取一个名叫 EventHandlersStore 的私有实例属性. 通过 GetValue() 方法获取这个属性的值. 然后获取 EventHandlersStore 类的一个方法叫做 GetRoutedEventHandlers. 执行这个方法来获取 eventHandlersStore 实例中的类型为 routedEvent
的handlers.

2. 如果有一个全局的资源, 例如一个List<string> 我们想要绑定到前台界面一个下拉框中. 做法如下:　

首先把这个资源放到 Application Resource 中.

System.Windows.Application.Current.Resources.Add("AllFlows", Launcher.AllFlows);

然后, 在 xaml 文件中将这个资源用 DynamicResource 绑定到控件上.

<MultiSelectComboBox x:Name="cboIgnoreFlows"  ItemsSource="{DynamicResource AllFlows}" SelectedValue="{Binding SelectedIgnoreFlows, Mode=TwoWay}">