.net - Windows 窗体线程和事件 - 传递事件的最有效方法？

Question

我的表单从随机工作线程上的另一个对象接收异步回调。我一直在使用委托(delegate)将数据传递给主线程(可用于更新屏幕控件)，如下所示。性能很糟糕——一旦我达到每秒 500 次更新，程序就会完全锁定。我的 GUI 处理本身不是问题，因为我可以在表单中模拟这种级别的更新并且没有问题。我应该使用更有效的机制将数据从线程传递到线程吗？

delegate void DStatus( MyStatus obj );
DStatus _status; // set to MainThreadOnStatus during construction

// this function only called on form's owner thread
void MainThreadOnStatus( MyStatus obj )
{
   // screen updates here as needed
}

// this function called by arbitrary worker threads in external facility
void OnStatus( MyStatus obj )
{
   this.BeginInvoke( _status, obj );
}

Answer 1

我不是计时器的忠实拥护者，如果您想要更多事件驱动的方法，请尝试以下操作:

public class Foo
{
    private AsyncOperation _asyncOperation = null;
    private SendOrPostCallback _notifyNewItem = null;

    //Make sure you call this on your UI thread.
    //Alternatively you can call something like the AttachUI() below later on and catch-up with
    //your workers later.
    public Foo()
    {
        this._notifyNewItem = new SendOrPostCallback(this.NewDataInTempList);
        this._asyncOperation = AsyncOperationManager.CreateOperation(this);
    }

    public void AttachUI()
    {
        if (this._asyncOperation != null)
        {
            this._asyncOperation.OperationCompleted();
            this._asyncOperation = null;
        }

        this._asyncOperation = AsyncOperationManager.CreateOperation(this);
        //This is for catching up with the workers if they’ve been busy already
        if (this._asyncOperation != null)
        {
            this._asyncOperation.Post(this._notifyNewItem, null);
        }
    }


    private int _tempCapacity = 500;
    private object _tempListLock = new object();
    private List<MyStatus> _tempList = null;

    //This gets called on the worker threads..
    //Keeps adding to the same list until UI grabs it, then create a new one.
    public void Add(MyStatus status)
    {
        bool notify = false;
        lock (_tempListLock)
        {
            if (this._tempList == null)
            {
                this._tempList = new List<MyStatus>(this._tempCapacity);
                notify = true;
            }

            this._tempList.Add(status);
        }
        if (notify)
        {
            if (this._asyncOperation != null)
            {
                this._asyncOperation.Post(this._notifyNewItem, null);
            }
        }
    }

    //This gets called on your UI thread.
    private void NewDataInTempList(object o)
    {
        List<MyStatus> statusList = null;
        lock (this._tempListLock)
        {
            //Grab the list, and release the lock as soon as possible.
            statusList = this._tempList;
            this._tempList = null;
        }
        if (statusList != null)
        {
            //Deal with it here at your leasure
        }
    }
}

我在一个自定义的 Log4Net 记录器中使用了它来收集日志条目并将它们添加到一个绑定(bind)到网格的循环数组中。性能最终表现得非常好。