如何使用Debugger（VS Professional 2012）查找事件列表？ [英] How to find list of events using Debugger (VS Professional 2012)?

问题描述

好的，我找不到任何帮助，我的问题stackoverflow似乎没有什么，或者我不知道如何寻找它（请纠正我，如果我错了，我会关闭这个问题）。

在我的程序中，我有一个 Grid ，其中有几个事件被隐藏在代码中：

  public Grid _grid = new Grid（）; 
 _grid.MouseLeftButtonDown + = new MouseButtonEventHandler（MyMethod）; 
 //还有一些事件... 
  

现在在我的程序运行中，我看到一些奇怪的行为，只能来自一些事件，所以我设置一个断点，并停止程序使用调试器。

有没有一个列表，我可以找到某个地方列出成员的所有当前定义的事件 _grid 所以我可以检查没有不需要的事件还没有被删除？

解决方案

更新2

不幸的是，WPF中的大多数事件（即 UIElement ）通过手动实现 add / remove 来实现，这意味着事件成员可以只能在 - = 或 + = 操作符的左侧（即不能读取 ）。内部是这样的，每个事件被委派到一个事件的集合，该集合只包含分配事件的元素（例如，如果有一个单独的 MouseLeftButtonDownEvent + = somehandler; 然后事件的集合只有一个条目，不幸的是，事件的集合存储来表示处理程序是一个内部结构，您必须能够实例化来查询集合。您无法实例化该结构的实例（ RoutedEventHandlerInfo ，FWIW），以便查询收藏（ UIElement.EventHandlersStore._entries ，也是FWIW），例如if您可以，您可以在QuickWatch窗口中查询特定事件的处理程序：

  grid.EventHandlersStore._entries [ 
 new RoutedEventHandlerInfo（UIElement.MouseLeftButtonDownEvent，false）] 
  

但是，调试器不允许你调用一个内部的构造函数。

事件没有列出 的东西。您可以在调试器（watch，quickwatch等）中查看实例的所有成员，并且事件具有不同的图标。然后，您可以展开其中的每一个，以查看分配给该事件的方法。例如：

如您所见， MyEvent 已被分配方法 t_MyEvent

更新：
如果您有多个事件处理程序分配给一个事件，那么调试器只会在快速监视中显示事件顶层的最后分配的方法。要查看所有分配的方法，您需要向下钻取到调用列表。例如：

..这表明 t_MyEvent 和 t_MyEvent2 都在 MyEvent 的调用列表。如果您没有处理程序，则 MyEvent 的值将为 null 。

Okay, I can't find any help for my question and stackoverflow doesn't seem to have anything either, or I didn't know how to look for it (please correct me, if I'm wrong and I will close this question).

In my program, I have a Grid which has a few events definded in code:

public Grid _grid = new Grid();
_grid.MouseLeftButtonDown += new MouseButtonEventHandler(MyMethod);
//and a few more events...

Now during my program run, I saw some weird behaviour that can only come from some events, so I set a breakpoint and stopped the program to use the debugger.

Is there a list I can find somewhere that lists all the currently defined events of the member _grid so I can check that no unwanted events have not yet been removed?

解决方案

Update 2

Unfortunately, most events in WPF (i.e. on UIElement) are implemented by manually implementing add/remove which means the event member can only be on the left hand side of a -= or += operator (i.e. it can't be "read"). The internals are such that each event is "delegated" to a collection of events and that collection only contains elements for assigned events (e.g. if there's a single MouseLeftButtonDownEvent += somehandler; then that collection of events will have only one entry. Unfortunately, what the collection of events stores to represent a handler is an internal structure that you would have to be able to instantiate to query the collection. You are unable to instantiate an instance of that structure (RoutedEventHandlerInfo, FWIW) in order to query the collection (UIElement.EventHandlersStore._entries, also FWIW). e.g. if you could you, you could query the handler for a particular event as such in the QuickWatch window:

grid.EventHandlersStore._entries[
    new RoutedEventHandlerInfo(UIElement.MouseLeftButtonDownEvent, false)]

But, the debugger does not allow you to invoke an internal constructor.

There isn't something that lists just the events. You can see all the members of a instance in the debugger (watch, quickwatch, etc.) and the events have a distinct icon. You can then expand each one of these to see what method was assigned to the event. For example:

As you can see, MyEvent has been "assigned" the method t_MyEvent for this particular instance.

Update: If you have more than one event handler assigned to an event, the debugger will only show the last assigned method in top-level of the event in quick watch. To see all the methods assigned, you'll need to drill-down to the invocation list. For example:

.. this shows that both t_MyEvent and t_MyEvent2 are in the invocation list for MyEvent. If you hace no handlers, the value for MyEvent will be null.

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