ModelChanged事件处理程序缺少事件参数 [英] ModelChanged event handler missing event args

问题描述

我在AddDesigner调用中实现了ModelChanged事件处理程序，如下所示:

I have implemented a ModelChanged event handler in my AddDesigner call as follows:

             _wd.ModelChanged += wd_ModelChanged;

ModelChanged事件的代码为:

The code for the ModelChanged event is:

private void wd_ModelChanged(object sender, EventArgs e)
        {
            ModelChangedEventArgs changedEventArgs = e as ModelChangedEventArgs;

            if(changedEventArgs != null)
            {
                IEnumerable<ModelItem> itemsRemoved = changedEventArgs.ItemsRemoved;

                foreach (ModelItem modelItem in itemsRemoved)
                {
                    if (modelItem.ItemType == typeof(Flowchart))
                    {
                        MessageBox.Show("You can not delete the base flow chart!", _appName, MessageBoxButton.OK, MessageBoxImage.Stop);
                    }
                }
            }

            //Add the expression text boxes to all switch and descision flow activities
            AddExpressionTextToFlowActivities();

            _wd.Flush();
        }

我的问题是，当我期望编辑上下文中有事件参数时，没有事件参数通过.关于遗漏的内容有什么想法吗?

The issue I have is that there are no event args coming through, when I expected there to be event arguments from the editing context. Any ideas on what I have missed?

推荐答案

这对API有点奇怪，但是我认为工作流程设计人员实际上知道确切的更改是什么.相反，您可以尝试订阅ModelService.ModelChanged，其中应该包含一些有用的事件信息.

Tim

This is a bit of a weirdness on the API, but I don't think the workflow designer actually knows what the exact changes are. Instead you can try subscribing to ModelService.ModelChanged, that one should have some useful event information.

Tim

这篇关于ModelChanged事件处理程序缺少事件参数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！