尝试:

private void onMyStoryBoardCompleted(object sender, object e)
{ }

并使用通用EventHandler<object>订阅:

myStoryBoard.Completed += new EventHandler<object>(onMyStoryBoardCompleted);

当然，这违反了.NET Framework约定，事件处理程序的第二个参数应为EventArgs的实例(或其派生类).我假设您正在另一个框架上运行，例如Windows 8 Metro，该框架的Timeline类定义了Understanding events and event handlers in C#

C# Dynamic template implicit conversion error from System.EventHandler to System.EventHandler<TEventArgs>

defining event handler for Tick event of DispatcherTimer in windows 8 app

But still don't find the solution for this case.

Thanks in advance.

Try:

private void onMyStoryBoardCompleted(object sender, object e)
{ }

And subscribe using the generic EventHandler<object>:

myStoryBoard.Completed += new EventHandler<object>(onMyStoryBoardCompleted);

Of course, this goes against the .NET Framework convention that the second argument to an event handler should be an instance of EventArgs (or a class derived thereof). I am assuming that you are running on another framework, such as Windows 8 Metro, whose Timeline class defines a Completed event with an EventHandler<object> signature.