跳过 675 帧！应用程序可能在其主线程上做了太多工作。如何在不冻结 UI 的情况下使应用 运行 在后台运行？

Question

我有一个新闻聚合器，在调试中我有以下内容： 跳过 675 帧！应用程序可能在其主线程上做了太多工作。 我只从 12 个站点加载。有没有办法在不冻结整个应用程序的情况下在后台完成所有这些加载？

编辑： 一则消息获取方法

public async static Task<NewsContent> oneNews(string category,string site)
    {
        if(sites.Count==0)
            addElements();

        GetNews gn = new GetNews(site,false);
        Random rn = new Random();

        var s = await gn.news(rn.Next(0,2));
        return s;
    }

GetNews class:

class GetNews
{

    string url;
    bool isMultiple;
    public GetNews(string url,bool isMultiple)
    {
        this.url = url;
        this.isMultiple = isMultiple;
    }


    public async Task<NewsContent> news(int i)
    {
        List<NewsContent> feedItemsList = new List<NewsContent>();

        try
        {
            WebRequest webRequest = WebRequest.Create(url);
            WebResponse webResponse = webRequest.GetResponse();
            Stream stream = webResponse.GetResponseStream();
            XmlDocument xmlDocument = new XmlDocument();
            xmlDocument.Load(stream);
            XmlNamespaceManager nsmgr = new XmlNamespaceManager(xmlDocument.NameTable);
            nsmgr.AddNamespace("dc", xmlDocument.DocumentElement.GetNamespaceOfPrefix("dc"));
            nsmgr.AddNamespace("content", xmlDocument.DocumentElement.GetNamespaceOfPrefix("content"));
            XmlNodeList itemNodes = xmlDocument.SelectNodes("rss/channel/item");
            NewsContent feedItem = new NewsContent();

                if (itemNodes[i].SelectSingleNode("title") != null)
                {
                    feedItem.title = itemNodes[i].SelectSingleNode("title").InnerText;
                }
                if (itemNodes[i].SelectSingleNode("link") != null)
                {
                    feedItem.url = itemNodes[i].SelectSingleNode("link").InnerText;
                }
                if (itemNodes[i].SelectSingleNode("pubDate") != null)
                {
                    var time = itemNodes[i].SelectSingleNode("pubDate").InnerText;
                    feedItem.time = getHour(time);
                }
                if (itemNodes[i].SelectSingleNode("description") != null)
                {
                    feedItem.desc = itemNodes[i].SelectSingleNode("description").InnerText;

                }
                if (itemNodes[i].SelectSingleNode("content:encoded", nsmgr) != null)
                {
                    feedItem.content = itemNodes[i].SelectSingleNode("content:encoded", nsmgr).InnerText;
                }
                else
                {
                    feedItem.content = feedItem.desc;
                }
                feedItem.imageURL = getImage(feedItem.content);


                var sourcename = url.Split(new[] { "//" }, StringSplitOptions.None)[1];
                feedItem.newsSource = sourcename.Split(new[] { "/" }, StringSplitOptions.None)[0];
                if (feedItem.content.Contains("<p>"))
                {
                    var shortContent = feedItem.content.Split(new[] { "<p>" }, StringSplitOptions.None)[1];
                    string finalShortContent = "";
                    for (int ii = 0; ii < shortContent.Length; ii++)
                    {
                        if (ii > 200 && shortContent[ii].Equals(' '))
                            break;
                        while (shortContent[ii].Equals('<') || shortContent[ii].Equals('p') || shortContent[ii].Equals('/') || shortContent[ii].Equals('>'))
                            ii++;
                        try
                        {
                            finalShortContent += shortContent[ii];
                        }
                        catch (Exception e)
                        {
                            break;
                        }
                    }
                    finalShortContent += "...";
                    feedItem.shortcontent = finalShortContent;
                }
            return feedItem;
        }
        catch (Exception e)
        {
            return null;
        }

    }
    string getImage(string full)
    {
        try
        {
            var code = full.Split(new[] { "src=\"" }, StringSplitOptions.None)[1];
            var fin = code.Split(new[] { "\"" }, StringSplitOptions.None)[0];
            return fin;
        }
        catch(Exception e)
        {
            return null;
        }
    }
    List<int> getHour(string full)
    {
        try
        {
            List<int> smh = new List<int>();
            var ph = full.Split(new[] { "2020 " }, StringSplitOptions.None)[1];
            var hour = ph.Split(new[] { ":" }, StringSplitOptions.None);
            smh.Add(Int32.Parse(hour[0]));
            smh.Add(Int32.Parse(hour[1]));
            var second = hour[2].Split(new[] { " " }, StringSplitOptions.None)[0];
            smh.Add(Int32.Parse(second));
            return smh;
        }catch(Exception)
        {
            return null;
        }
    }
}

Answer 1

试试这个。它应该将函数放在另一个线程中

await Task.Run(async () =>
                    {
                        //function
                    });