如何限制 Parallel.ForEach？ - How can I limit Parallel.ForEach?

問題：

I have a Parallel.ForEach() async loop with which I download some webpages.我有一個 Parallel.ForEach() 非同步迴圈，我用它下載了一些網頁。 My bandwidth is limited so I can download only x pages per time but Parallel.ForEach executes whole list of desired webpages.我的頻寬有限，所以我每次只能下載 x 頁，但 Parallel.ForEach 執行所需網頁的整個列表。

Is there a way to limit thread number or any other limiter while running Parallel.ForEach?有沒有辦法在執行 Parallel.ForEach 時限制執行緒數或任何其他限制器？

Demo code:演示程式碼：

Parallel.ForEach(listOfWebpages, webpage => {
  Download(webpage);
});

The real task has nothing to do with webpages, so creative web crawling solutions won't help.真正的任務與網頁無關，因此創造性的網路抓取解決方案無濟於事。

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解決方案：

參考一： http://stackoom.com/question/cysk
參考二： How can I limit Parallel.ForEach?