.NET Framework,WPF：取消函数引发事件

Question

我有一个函数来处理一个事件

public void Delete(bool raiseEvent)
{
       if (raiseEvent)
       {
           RaiseEvent(new EdgeDeletedRoutedEventArgs(DeletedEvent, this));
       }
       ....some other stuff
}

我订阅该功能如下：

Class.Delete += SomethingDeleted;

void SomethingDeleted(object sender, EdgeDeletedRoutedEventArgs e)
{
    if (someCondition)
    {
        // here i want to cancel the delete function which raises the event
    }  
}

怎么可能取消删除功能，这样“其他东西”就不会在不中断我的应用程序的情况下执行呢？

我尝试在SomethingDeleted中抛出一个异常，并在Delete中捕获该异常，但它中断了我的应用程序和id，以保持应用程序运行。

Answer 1

将bool cancel属性添加到EdgeDeletedRoutedEventArgs（与CancelEventArgs一样）

public void Delete(bool raiseEvent)
{
       if (raiseEvent)
       {
           var args = new EdgeDeletedRoutedEventArgs(DeletedEvent, this);
           RaiseEvent(args);
           if (args.Cancel) return;
       }
       ....some other stuff
}

void SomethingDeleted(object sender, EdgeDeletedRoutedEventArgs e)
{
    if (someCondition)
    {
         e.Cancel = true;
         return;
    }  
}

如果您不真正需要RoutedEvent功能，请使用常规事件(event EventHandler Delete； )并从CancelEventArgs继承EdgeDeletedEventArgs