如何在 TPL 数据流中将多个目标块与源块链接？

Question

我预计以下内容会从两个发布者产生输出，但它只产生第一个发布者的输出：

var broadcastBlock = new BroadcastBlock<int>(null);
var transformBlock = new TransformBlock<int, int>(i => i*10);
var publish1 = new ActionBlock<int>(i => Console.WriteLine("Publisher 1:" + i));
var publish2 = new ActionBlock<int>(i => Console.WriteLine("Publisher 2:" + i));

broadcastBlock.LinkTo(transformBlock, new DataflowLinkOptions() { PropagateCompletion = true });
transformBlock.LinkTo(publish1, new DataflowLinkOptions() { PropagateCompletion = true });
transformBlock.LinkTo(publish2, new DataflowLinkOptions() { PropagateCompletion = true });

foreach (var i in Enumerable.Range(0, 5))
{
    broadcastBlock.Post(i);
}
broadcastBlock.Complete();
Task.WhenAll(publish1.Completion, publish2.Completion).Wait();

我显然在这里遗漏了一些基本的东西，有什么想法吗？

Answer 1

您将 2 个ActionBlocks 链接到一个TransformBlock。您应该将 2 个 ActionBlocks 链接到 BrodcastBlock 并将 BroadcastBlock 链接到 TransformBlock。

你有什么：

BroadCast => Transfrom => ActionBlock
                       => ActionBlock

你需要什么：

Transfrom => BroadCast => ActionBlock
                       => ActionBlock