翻译自In WPF, how to debug triggers?
本来不想发的，但搜索了一下国内好像没人写这个，so.......
效果如图
工作原理
使用附加属性将虚拟动画storyboards添加到触发器
激活WPF动画跟踪并将结果过滤到仅包含storyboards
TriggerTracing
将TriggerTracing添加到项目中
/// <summary>
/// Contains attached properties to activate Trigger Tracing on the specified Triggers.
/// 包含附加属性以激活指定触发器上的触发器跟踪
/// This file alone should be dropped into your app.
/// 仅此文件应放入您的应用程序
/// </summary>
public static class TriggerTracing
{
static TriggerTracing()
{
// Initialise WPF Animation tracing and add a TriggerTraceListener
//初始化WPF动画跟踪并添加TriggerTraceListener
PresentationTraceSources.Refresh();
PresentationTraceSources.AnimationSource.Listeners.Clear();
PresentationTraceSources.AnimationSource.Listeners.Add(new TriggerTraceListener());
PresentationTraceSources.AnimationSource.Switch.Level = SourceLevels.All;
}
#region TriggerName attached property
/// <summary>
/// Gets the trigger name for the specified trigger. This will be used
/// to identify the trigger in the debug output.
/// 获取指定触发器的触发器名称。 这将用于在调试输出中标识触发器。
/// </summary>
/// <param name="trigger">The trigger.</param>
/// <returns></returns>
public static string GetTriggerName(TriggerBase trigger)
{
return (string)trigger.GetValue(TriggerNameProperty);
}
/// <summary>
/// Sets the trigger name for the specified trigger. This will be used
/// to identify the trigger in the debug output.
/// 设置指定触发器的触发器名称。 这将用于在调试输出中标识触发器。
/// </summary>
/// <param name="trigger">The trigger.</param>
/// <returns></returns>
public static void SetTriggerName(TriggerBase trigger, string value)
{
trigger.SetValue(TriggerNameProperty, value);
}
public static readonly DependencyProperty TriggerNameProperty =
DependencyProperty.RegisterAttached(
"TriggerName",
typeof(string),
typeof(TriggerTracing),
new UIPropertyMetadata(string.Empty));
#endregion
#region TraceEnabled attached property
/// <summary>
/// Gets a value indication whether trace is enabled for the specified trigger.
/// 获取一个值指示是否为指定的触发器启用跟踪
/// </summary>
/// <param name="trigger">The trigger.</param>
/// <returns></returns>
public static bool GetTraceEnabled(TriggerBase trigger)
{
return (bool)trigger.GetValue(TraceEnabledProperty);
}
/// <summary>
/// Sets a value specifying whether trace is enabled for the specified trigger
/// 设置一个值，该值指定是否为指定的触发器启用跟踪
/// </summary>
/// <param name="trigger"></param>
/// <param name="value"></param>
public static void SetTraceEnabled(TriggerBase trigger, bool value)
{
trigger.SetValue(TraceEnabledProperty, value);
}
public static readonly DependencyProperty TraceEnabledProperty =
DependencyProperty.RegisterAttached(
"TraceEnabled",
typeof(bool),
typeof(TriggerTracing),
new UIPropertyMetadata(false, OnTraceEnabledChanged));
private static void OnTraceEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var triggerBase = d as TriggerBase;
if (triggerBase == null)
return;
if (!(e.NewValue is bool))
return;
if ((bool)e.NewValue)
{
// insert dummy story-boards which can later be traced using WPF animation tracing
//添加虚拟storyboards，以后可以使用WPF动画跟踪对其进行跟踪
var storyboard = new TriggerTraceStoryboard(triggerBase, TriggerTraceStoryboardType.Enter);
triggerBase.EnterActions.Insert(0, new BeginStoryboard() { Storyboard = storyboard });
storyboard = new TriggerTraceStoryboard(triggerBase, TriggerTraceStoryboardType.Exit);
triggerBase.ExitActions.Insert(0, new BeginStoryboard() { Storyboard = storyboard });
}
else
{
// remove the dummy storyboards
//移除虚拟storyboards
foreach (TriggerActionCollection actionCollection in new[] { triggerBase.EnterActions, triggerBase.ExitActions })
{
foreach (TriggerAction triggerAction in actionCollection)
{
BeginStoryboard bsb = triggerAction as BeginStoryboard;
if (bsb != null && bsb.Storyboard != null && bsb.Storyboard is TriggerTraceStoryboard)
{
actionCollection.Remove(bsb);
break;
}
}
}
}
}
#endregion
/// <summary>
/// 触发器跟踪Storyboard类型
/// </summary>
private enum TriggerTraceStoryboardType
{
//进入
Enter,
//退出
Exit
}
/// <summary>
/// A dummy storyboard for tracing purposes
/// 用于跟踪的虚拟storyboard
/// </summary>
private class TriggerTraceStoryboard : Storyboard
{
public TriggerTraceStoryboardType StoryboardType { get; private set; }
public TriggerBase TriggerBase { get; private set; }
public TriggerTraceStoryboard(TriggerBase triggerBase, TriggerTraceStoryboardType storyboardType)
{
TriggerBase = triggerBase;
StoryboardType = storyboardType;
}
}
/// <summary>
/// A custom tracelistener.
/// 自定义跟踪侦听器
/// </summary>
private class TriggerTraceListener : TraceListener
{
public override void TraceEvent(TraceEventCache eventCache, string source, TraceEventType eventType, int id, string format, params object[] args)
{
base.TraceEvent(eventCache, source, eventType, id, format, args);
if (format.StartsWith("Storyboard has begun;"))
{
TriggerTraceStoryboard storyboard = args[1] as TriggerTraceStoryboard;
if (storyboard != null)
{
// add a breakpoint here to see when your trigger has been
// entered or exited
//在此处添加断点，以查看何时输入或退出触发器
// the element being acted upon
//被作用的元素
object targetElement = args[5];
// the namescope of the element being acted upon
//所作用元素的名称范围
INameScope namescope = (INameScope)args[7];
TriggerBase triggerBase = storyboard.TriggerBase;
//获得TriggerTracing.TriggerName
string triggerName = GetTriggerName(storyboard.TriggerBase);
Debug.WriteLine(string.Format("Element: {0}, {1}: {2}: {3}",
targetElement,
triggerBase.GetType().Name,
triggerName,
storyboard.StoryboardType));
}
}
}
public override void Write(string message)
{
}
public override void WriteLine(string message)
{
}
}
}
使用
将以下附加属性添加到任何触发器，将在输出窗口中看到它何时被激活/停用
TriggerTracing.TriggerName="your debug name"
TriggerTracing.TraceEnabled="True"
例子
<Trigger my:TriggerTracing.TriggerName="BoldWhenMouseIsOver"
my:TriggerTracing.TraceEnabled="True"
Property="IsMouseOver"
Value="True">
<Setter Property = "FontWeight" Value="Bold"/>
</Trigger>