对象接收器事件循环自身 [英] Object receiver event looping on itself

问题描述

  if （searchSubmit ==  false ）
 {
 webBrowser1.DocumentCompleted + = 
  new  WebBrowserDocumentCompletedEventHandler（OnDocumentCompleted）; 
} 
  else  
 {
 webBrowser1.Stop（）; 
} 
 
 
} 
 
  private   void  OnDocumentCompleted（ object  receiver，WebBrowserDocumentCompletedEventArgs e）
 {
 HtmlElementCollection avCollection = webBrowser1.Document.GetElementById（  filterAvailability）。GetElementsByTagName（ 选项）; 
 
列表< HtmlElement> avList =  new 列表< HtmlElement>（）; 
  foreach （HtmlElement avItem  in  avCollection）
 {
 avList。加入（avItem）; 
} 
 
 HtmlElement avElement = 
（HtmlElement）avList.Where（avOption = >  avOption.GetAttribute（< span class =code-string>  value）。等于（ < span class =code-string> 1））。SingleOrDefault（）; 
 
  if （avElement.GetAttribute（  value）。Equals（  1））
 {
 avElement.SetAttribute（  Selected，  1）; 
 avElement.InvokeMember（ 点击）; 
} 
 
 bookCollection = webBrowser1.Document.GetElementsByTagName（  button）; 
  foreach （HtmlElement curElement  in  bookCollection）
 {
  if （curElement.GetAttribute（  id） .Equals（  searchSubmit））
 {
 curElement.InvokeMember（< span class =code-string>  click）; 
} 
} 
 searchSubmit =  true ; 
 
  if （searchSubmit ==  true ）
 {
 webBrowser1.Stop（）; 
} 
} 

问题是即使我设置了bool变量，偶数也会循环。我注意到这一点，因为页面保持刷新，因为有searchSumbit Click调用成员。如何让代码只运行一次？



谢谢





添加了代码块 - OriginalGriff [/ edit]

解决方案

可能每次用户按下按钮时都不想添加新的处理程序，你现在似乎在做什么。



您是否意识到事件的+ =会为链添加处理程序？如果你在链中有相同的处理程序8次，每次事件被触发时它会被调用8次？

添加一次，或者在你不再需要它时删除它

if (searchSubmit == false)
            {
                webBrowser1.DocumentCompleted +=
                    new WebBrowserDocumentCompletedEventHandler(OnDocumentCompleted);
            }
            else
            {
                webBrowser1.Stop();
            }


        }
            
     private void OnDocumentCompleted(object receiver, WebBrowserDocumentCompletedEventArgs e)
        {
            HtmlElementCollection avCollection = webBrowser1.Document.GetElementById("filterAvailability").GetElementsByTagName("option");

            List<HtmlElement> avList = new List<HtmlElement>();
            foreach(HtmlElement avItem in avCollection)
            {
                avList.Add(avItem);
            }

            HtmlElement avElement =
                (HtmlElement)avList.Where(avOption => avOption.GetAttribute("value").Equals("1")).SingleOrDefault();

            if (avElement.GetAttribute("value").Equals("1"))
            {
                avElement.SetAttribute("Selected", "1");
                avElement.InvokeMember("click");
            }

            bookCollection = webBrowser1.Document.GetElementsByTagName("button");
            foreach (HtmlElement curElement in bookCollection)
            {
                if (curElement.GetAttribute("id").Equals("searchSubmit"))
                {
                    curElement.InvokeMember("click");
                }
            }
            searchSubmit = true;

         if (searchSubmit == true)
         {
             webBrowser1.Stop();
         }
        }

The problem is the even is looping all the time even if I set a bool variable. I noticed this because the page keeps refreshing since there is the searchSumbit Click invoke member. how do i make the code run only once?.

Thanks


[edit]Code block added - OriginalGriff[/edit]

解决方案

Probably, you don't want to add a new handler each time the user presses the button, as you appear to be doing now.

You do realize that "+=" for an event adds a handler to the chain? And that if you have the same handler in the chain 8 times, it will get called eight times every time the event is fired?
Add it once, or remove it when you don't need it anymore.

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