CommandBars.OnUpdate停止触发 [英] CommandBars.OnUpdate stops being fired

问题描述

在我的PowerPoint 2010 Addin中，我订阅了 CommandBars.OnUpdate 事件来注册形状和类似事件的移动：

In my PowerPoint 2010 Addin I subscribed to the CommandBars.OnUpdate event to register movement of shapes and similar events:

 ppt = Globals.ThisAddIn.Application;
 ppt.CommandBars.OnUpdate += CommandBars_OnUpdate;

这段时间很好。但是，最终事件停止被解雇。那么，至少注册的事件处理程序没有被调用。我不清楚，是什么原因导致这种行为。看起来有点不确定。调试输出中不会出现异常。看来，这种情况发生在一段时间之后，不是由用户操作引起的。

This works great for some time. However, eventually the event stops being fired. Well, at least the registered event handler is not being called. I couldn't figure out, what causes this behaviour. It seems a bit indeterministic. No exception is thrown that would appear in the Debug output. It seems, this happens after some time and is not caused by a user action.

我假设，这是由于 CommandBars 对象。所以我添加了一个定时器，它检查这些更改。但是，与最后一个对象的比较， == 和 .Equals（）会导致每个刻度的识别更改，即非常不太可能。

I assumed, this would be due to a change of the CommandBars object. So I added a timer, which checked for those changes. But both == and .Equals() comparisons to the last object result in a recognized change every tick, which is very unlikely.

我也试图定期刷新事件处理程序（每1分钟），但这也不行：

I also tried to refresh the event handler periodically (every 1 minute), but this doesn't work either:

ppt.CommandBars.OnUpdate -= CommandBars_OnUpdate;
ppt.CommandBars.OnUpdate += CommandBars_OnUpdate;

事件真的在一段时间后停止吗？有没有其他方法可以检测物体移动，调整大小，删除等？

Does the event really stop after some time? Is there any other method to detect object movement, resize, deletion etc.?

同时我重组了加载项。我现在能够重现这个问题。这是如何：

In the meanwhile I restructured the addin. I am now able to reproduce the problem. Here is how:

在加载项的功能区中，我有一个按钮，它调用方法 CreateRightEyeCopy（）视图模型。在该方法中，调用ViewModel的另一种方法 GetNextPairId（）。这个电话似乎有问题。我更改了 GetNextPairId（）以立即返回0，以确保该方法是问题。

In the addin's ribbon I have a button, which calls the method CreateRightEyeCopy() on the ViewModel. In this method another method GetNextPairId() of the ViewModel is called. And this call seems problematic. I changed the GetNextPairId() to immediately return 0 to ensure that the method is the problem.

这是 return 0 line

ViewModel.GetNextPairId()
[External Code]
ViewModel.CreateRightEyeCopy()
Button's event handler

$ b $我不知道为什么我的两个功能之间有外部代码。这个代码可以导致 OnUpdate 事件停止吗？

如果有人有兴趣，这里是两个函数的代码：

If someone's interested, here is the code of the two functions:

CreateRightEyeCopy（）：

try
{
    var sel = ppt.ActiveWindow.Selection;
    if (sel.Type == PpSelectionType.ppSelectionShapes)
    {
        foreach (Shape s in sel.ShapeRange)
        {
            var pair = FindStereoPair(s);
            //Only add a new pair, if shape is not in a pair already
            if (pair == null)
            {
                // ** return; **
                int id = GetNextPairId(s.Parent);
                return; //for debugging purposes
            }
        }
    }
}
catch (Exception x)
{
    Debug.WriteLine("Exception occured during creation of stereo pair: " + x.Message);
}

GetNextPairId（） ：

return 0;

如果在调用 GetNextPairId（）然后 OnUpdate 继续。

我还试图调用 CreateRightEyeCopy （）异步地，但这并不改变任何东西。

I also tried to invoke CreateRightEyeCopy() asynchronously, but that doesn't change anything.

在这个问题上是否有进一步的想法？

Are there any further thoughts on this issue?

推荐答案

不是真正的答案，而是 MSDN说：强烈建议此事件主要用于检查COM AddIn中添加或删除的自定义命令栏。

Not a real answer but MSDN says: "It is strongly recommended that this event be used primarily for checking that a custom command bar has been added or removed by a COM AddIn."

您应该选择不同的方法来跟踪其他事件。

You should probably choose a different approach to track other events.

作为事后，您确定您捕获所有异常（UnhandledException，ThreadException ）？

As an afterthought, are you sure you are capturing all exceptions (UnhandledException, ThreadException)?

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