如何从外部线程调用兄弟对象

Question

我有一个包含大量用户控件的 WPF 应用程序。其中一个控件还使用第三方 DLL，该 DLL 监视外部系统并产生事件。我订阅了这些事件并通过以下方式处理它们：

public class ControlClassD
{
    private 3rdPartyEventSource _3rdPartyEventSource = new 3rdPartyEventSource();

    public ControlClassD()
    {
        _3rdPartyEventSource.NewEvent += _3rdPartyEventSource_NewEvent;
        _3rdPartyEventSource.StartMakingEventsWhenSomethingHappens();
    }

    private void _3rdPartyEventSource_NewEvent(object o)
    {
        InstanceOfControlClassA.doSomethingWith(o);
        InstanceOfControlClassB.doSomethingWith(o);
        InstanceOfControlClassC.doSomethingWith(o);
    }
}

所有 InstanceOfControlClassx 都由启动时在 MainWindow 类中运行 _Loaded 事件处理程序的任何线程实例化。

执行处理程序的线程是由 3rdPartyEventSource 创建的，无法访问所有这些东西（如该性质的错误消息所示）

我想做的是让 3rdPartyEventSource 传递的线程返回并让创建所有这些实例的线程 (CreatorThread) 执行 HandleNewEvent。喜欢：

    private void _3rdPartyEventSource_NewEvent(object o)
    {
        SomehowInvokeCreatorThread(new Action(() => HandleNewEvent(o)));
    }

    private void HandleNewEvent(object o)
    {
        InstanceOfControlClassA.doSomethingWith(o);
        InstanceOfControlClassB.doSomethingWith(o);
        InstanceOfControlClassC.doSomethingWith(o);  //which may access this
    }

我该怎么做？

Answer 1

有很多方法可以做到这一点，但以下一种可能是最简单的。只需创建您自己的包装事件，该事件将在 UI 线程上触发：

public class ControlClassD
{
    public class WrapperEventArgs: EventArgs { public object Arg { get; set; } }
    public event EventHandler<WrapperEventArgs> WrapperEvent = delegate { };

    private 3rdPartyEventSource _3rdPartyEventSource = new 3rdPartyEventSource();

    public ControlClassD()
    {
        var dispatcher = Dispatcher.CurrentDispatcher;

        _3rdPartyEventSource.NewEvent += obj =>
              dispatcher.BeginInvoke(new Action(() => 
                  this.WrapperEvent(this, new WrapperEventArgs { Arg = obj })));

        this.WrapperEvent += ControlClassD_WrapperEventHandler;

        _3rdPartyEventSource.StartMakingEventsWhenSomethingHappens();
    }

    private void ControlClassD_WrapperEventHandler(
        object sender, WrapperEventArgs args)
    {
        InstanceOfControlClassA.doSomethingWith(args.Arg);
        InstanceOfControlClassB.doSomethingWith(args.Arg);
        InstanceOfControlClassC.doSomethingWith(args.Arg);
    }
}