WPF Dispatcher 的 InvokeAsync 和 BeginInvoke 有什么区别 [英] What's the difference between InvokeAsync and BeginInvoke for WPF Dispatcher

问题描述

我注意到在 .NET 4.5 中 WPF Dispatcher一组新的方法，用于在 Dispatcher 的线程上执行名为 InvokeAsync 的内容.在 .NET 4.5 之前，我们有 调用 和 BeginInvoke 分别同步和异步处理.

I noticed in .NET 4.5 that the WPF Dispatcher had gotten a new set of methods to execute stuff on the Dispatcher's thread called InvokeAsync. Before, .NET 4.5 we had Invoke and BeginInvoke which handled this syncronously and asynchronously respectively.

除了命名和可用的重载略有不同之外，BeginInvoke 和 InvokeAsync 方法之间有什么主要区别吗?

Besides the naming and the slightly different overloads available, are there any major differences between the BeginInvoke and the InvokeAsync methods?

哦，我已经检查过了，两者都可以awaited:

Oh, and I already checked, both can be awaited:

private async Task RunStuffOnUiThread(Action action)
{
    // both of these works fine
    await dispatcher.BeginInvoke(action);
    await dispatcher.InvokeAsync(action);
}

推荐答案

没有区别，因为 BeginInvoke 方法调用私有的 LegacyBeginInvokeImpl 方法，而它的lef 调用私有方法InvokeAsyncImpl(InvokeAsync 使用的方法).所以它基本上是一样的.看起来这是一个简单的重构，但奇怪的是 BeginInvoke 方法没有被标记为过时.

There are no differences as the BeginInvoke method calls a private LegacyBeginInvokeImpl method which itslef calls the private method InvokeAsyncImpl (the method used by InvokeAsync). So it's basically the same thing. It seems like it's a simple refactoring, however it's strange the BeginInvoke methods weren't flagged as obsolete.

开始调用:

public DispatcherOperation BeginInvoke(DispatcherPriority priority, Delegate method)
{
    return this.LegacyBeginInvokeImpl(priority, method, null, 0);
}

private DispatcherOperation LegacyBeginInvokeImpl(DispatcherPriority priority, Delegate method, object args, int numArgs)
{
    Dispatcher.ValidatePriority(priority, "priority");
    if (method == null)
    {
        throw new ArgumentNullException("method");
    }
    DispatcherOperation dispatcherOperation = new DispatcherOperation(this, method, priority, args, numArgs);
    this.InvokeAsyncImpl(dispatcherOperation, CancellationToken.None);
    return dispatcherOperation;
}

调用异步:

public DispatcherOperation InvokeAsync(Action callback, DispatcherPriority priority)
{
    return this.InvokeAsync(callback, priority, CancellationToken.None);
}

public DispatcherOperation InvokeAsync(Action callback, DispatcherPriority priority, CancellationToken cancellationToken)
{
    if (callback == null)
    {
        throw new ArgumentNullException("callback");
    }
    Dispatcher.ValidatePriority(priority, "priority");
    DispatcherOperation dispatcherOperation = new DispatcherOperation(this, priority, callback);
    this.InvokeAsyncImpl(dispatcherOperation, cancellationToken);
    return dispatcherOperation;
}

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