等待变量更改VB.Net中状态的更好方法 [英] A better way to wait for a variable to change state in VB.Net

问题描述

我有一个遍历许多值的循环.迭代每个值后，将页面加载到webbrowser控件中(将值作为参数传递)，并在加载和读取页面时，循环应转到列表中的下一个值，并继续进行，直到处理完所有值为止.我需要一种方法来在网站异步加载时暂停该过程，然后在页面加载/阅读过程完成后恢复.

I have a loop that goes through a number of values. With every value iterated, a page is loaded in a webbrowser control (with the value passed as a parameter) and when the page is loaded and read, the loop should go to the next value in the list and continue until all values are processed. I need a way to pause the procedure while the website is loading asynchronously and then resume once the page loading/reading process is complete.

我正在做的事情是使用类似这样的东西，其中"ReadingInProgress"是一个全局变量:

The way I am doing is by using something like this, where "ReadingInProgress" is a global variable:

      ReadingInProgress = True
      wb.Navigate("http://mywebsite.com/mypage.aspx" & c)

      While ReadingInProgress
        Application.DoEvents()
      End While

webrowser控件的"DocumentCompleted"事件将"ReadingInProgress"设置为false，这将导致while循环退出并继续执行该过程.这行得通，但是我意识到这给CPU带来了压力.是否有更好的，较少占用CPU的方法来做到这一点?

The "DocumentCompleted" event of the webrowser control set "ReadingInProgress" to false which causes the while loop to exit and resume the procedure. This works, but I realize that it puts a strain on the CPU. Is there a better, less CPU intensive way to do this?

谢谢！

推荐答案

我最近回答了以非常相似的方式.使用此技术，您将获得自然的代码执行流(DocumentComplete事件被封装为Task).

I've recently answered a similar question. The solution is in C#, but you can use Async/Await in VB.NET in a very similar way. Using this technique, you would get a natural flow of execution for your code (DocumentComplete event is encapsulated as Task).

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