下面是我如何使用簡單的事件管理器鉤住UI事件並提取事件的關鍵信息（如UI元素的名稱和類型，事件名稱以及父窗口的類型名稱）的示例。對於列表我也提取選定的項目。
此解決方案只偵聽從ButtonBase（Button，ToggleButton，...）派生的控件的點擊和從Selector（ListBox，TabControl，...）派生的控件中的選擇更改。應該很容易擴展到其他類型的UI元素或實現更細粒度的解決方案。該解決方案受到Brad Leach's answer的啓發。
public class UserInteractionEventsManager
{
public delegate void ButtonClickedHandler(DateTime time, string eventName, string senderName, string senderTypeName, string parentWindowName);
public delegate void SelectorSelectedHandler(DateTime time, string eventName, string senderName, string senderTypeName, string parentWindowName, object selectedObject);
public event ButtonClickedHandler ButtonClicked;
public event SelectorSelectedHandler SelectorSelected;
public UserInteractionEventsManager()
{
EventManager.RegisterClassHandler(typeof(ButtonBase), ButtonBase.ClickEvent, new RoutedEventHandler(HandleButtonClicked));
EventManager.RegisterClassHandler(typeof(Selector), Selector.SelectionChangedEvent, new RoutedEventHandler(HandleSelectorSelected));
}
#region Handling events
private void HandleSelectorSelected(object sender, RoutedEventArgs e)
{
// Avoid multiple events due to bubbling. Example: A ListBox inside a TabControl will cause both to send the SelectionChangedEvent.
if (sender != e.OriginalSource) return;
var args = e as SelectionChangedEventArgs;
if (args == null || args.AddedItems.Count == 0) return;
var element = sender as FrameworkElement;
if (element == null) return;
string senderName = GetSenderName(element);
string parentWindowName = GetParentWindowTypeName(sender);
DateTime time = DateTime.Now;
string eventName = e.RoutedEvent.Name;
string senderTypeName = sender.GetType().Name;
string selectedItemText = args.AddedItems.Count > 0 ? args.AddedItems[0].ToString() : "<no selected items>";
if (SelectorSelected != null)
SelectorSelected(time, eventName, senderName, senderTypeName, parentWindowName, selectedItemText);
}
private void HandleButtonClicked(object sender, RoutedEventArgs e)
{
var element = sender as FrameworkElement;
if (element == null) return;
string parentWindowName = GetParentWindowTypeName(sender);
DateTime time = DateTime.Now;
string eventName = e.RoutedEvent.Name;
string senderTypeName = sender.GetType().Name;
string senderName = GetSenderName(element);
if (ButtonClicked != null)
ButtonClicked(time, eventName, senderName, senderTypeName, parentWindowName);
}
#endregion
#region Private helpers
private static string GetSenderName(FrameworkElement element)
{
return !String.IsNullOrEmpty(element.Name) ? element.Name : "<no item name>";
}
private static string GetParentWindowTypeName(object sender)
{
var parent = FindParent<Window>(sender as DependencyObject);
return parent != null ? parent.GetType().Name : "<no parent>";
}
private static T FindParent<T>(DependencyObject item) where T : class
{
if (item == null)
return default(T);
if (item is T)
return item as T;
DependencyObject parent = VisualTreeHelper.GetParent(item);
if (parent == null)
return default(T);
return FindParent<T>(parent);
}
#endregion
}
爲了進行實際的日誌記錄，我使用log4net並創建了一個名爲'Interaction'的單獨記錄器來記錄用戶交互。這裏的類'Log'只是我自己的log4net的靜態包裝器。
/// <summary>
/// The user interaction logger uses <see cref="UserInteractionEventsManager"/> to listen for events on GUI elements, such as buttons, list boxes, tab controls etc.
/// The events are then logged in a readable format using Log.Interaction.Info().
/// </summary>
public class UserInteractionLogger
{
private readonly UserInteractionEventsManager _events;
private bool _started;
/// <summary>
/// Create a user interaction logger. Remember to Start() it.
/// </summary>
public UserInteractionLogger()
{
_events = new UserInteractionEventsManager();
}
/// <summary>
/// Start logging user interaction events.
/// </summary>
public void Start()
{
if (_started) return;
_events.ButtonClicked += ButtonClicked;
_events.SelectorSelected += SelectorSelected;
_started = true;
}
/// <summary>
/// Stop logging user interaction events.
/// </summary>
public void Stop()
{
if (!_started) return;
_events.ButtonClicked -= ButtonClicked;
_events.SelectorSelected -= SelectorSelected;
_started = false;
}
private static void SelectorSelected(DateTime time, string eventName, string senderName, string senderTypeName, string parentWindowTypeName, object selectedObject)
{
Log.Interaction.Info("{0}.{1} by {2} in {3}. Selected: {4}", senderTypeName, eventName, senderName, parentWindowTypeName, selectedObject);
}
private static void ButtonClicked(DateTime time, string eventName, string senderName, string senderTypeName, string parentWindowTypeName)
{
Log.Interaction.Info("{0}.{1} by {2} in {3}", senderTypeName, eventName, senderName, parentWindowTypeName);
}
}
輸出會看起來像這樣，省略了不相關的日誌條目。
04/13 08:38:37.069 INFO Iact ToggleButton.Click by AnalysisButton in MyMainWindow
04/13 08:38:38.493 INFO Iact ListBox.SelectionChanged by ListView in MyMainWindow. Selected: Andreas Larsen
04/13 08:38:44.587 INFO Iact Button.Click by EditEntryButton in MyMainWindow
04/13 08:38:46.068 INFO Iact Button.Click by OkButton in EditEntryDialog
04/13 08:38:47.395 INFO Iact ToggleButton.Click by ExitButton in MyMainWindow
EventManager.RegisterClassHandler真的奏效了，當我需要做一些互動日誌記錄點擊按鈕，列表選擇等非常需要一些代碼來鉤在整個GUI必要的事件。 – angularsen 2011-04-11 07:08:29