Question

我有一个程序，其中有一个名为＆＃34; research＆＃34;当按下该按钮时，它会从输入文本框中读取，该文本框可能会显示＆＃34;如何*＆＃34;

它开始从google中提取自动建议，星号被字母表中的每个字母替换。

我的问题是：

我想要一个按钮来停止搜索。虽然它在运动中。

实现这一目标的最佳方法是什么？

private void btnResearch_Click(object sender, RoutedEventArgs e)
        {            
            if (string.IsNullOrWhiteSpace(txtResearch.Text.Trim()))
            {
                MessageBox.Show("Please enter a search query", "Oops", MessageBoxButton.OK, MessageBoxImage.Exclamation);
                return;              
            }
            //Robin: Temporal fix to the multi asterisk
            if (txtResearch.Text.Trim().Count(s => s == '*') > 1)
            {
                MessageBox.Show("Too many asterisk", "Oops", MessageBoxButton.OK, MessageBoxImage.Exclamation);
                return;            
            }

            if (!ValidateLimitations())
            {
                return;
            }

            ((LongTailBot.MainWindow)App.Current.MainWindow).PlaySound("button_double_click.wav");

            this.chbSelAll.IsChecked = false;
            List<KeywordItem> keyList = new List<KeywordItem>();
            this.dgrResearch.ItemsSource = null;

            List<string> seetKeywords = SetupSeetKeywords(txtResearch.Text.Trim().Replace(" ", "%20"));
            if (seetKeywords.Count() < 1)
                return;

            foreach (string seetKey in seetKeywords)
            {
                this.txbResearch.Text = (seetKeywords.IndexOf(seetKey) + 1).ToString()
                    + "/" + seetKeywords.Count() + " " + seetKey.Replace("%20", " ");
                Application.Current.Dispatcher.Invoke(DispatcherPriority.Background,
                                                      new Action(delegate { }));

                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(this.GetRequestUriString(seetKey));
                request.Method = "GET";
                request.UserAgent = @"Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.0; Trident/5.0)";
                WebResponse response = request.GetResponse();

                if (((HttpWebResponse)response).StatusDescription.Trim().ToUpper() == "OK")
                {
                    using (Stream dataStream = response.GetResponseStream())
                    {
                        using (StreamReader reader = new StreamReader(dataStream))
                        {
                            string responseFromServer = reader.ReadToEnd();

                            var keywordsFound = this.GetKeywordsFound(responseFromServer);
                            foreach (var key in keywordsFound)
                            {
                                keyList.RemoveAll(k => k.Keyword == key);                                                                
                                keyList.Add(new KeywordItem() { Checked = false, Keyword = key });

                                Application.Current.Dispatcher.Invoke(DispatcherPriority.Background,
                                          new Action(delegate { }));                                
                            }

                        }
                    }
                    if (keyList.Count > 0)
                    {
                        dgrResearch.ItemsSource = null;
                        dgrResearch.ItemsSource = keyList;
                        dgrResearch.ScrollIntoView(dgrResearch.Items[dgrResearch.Items.Count - 1]);                        
                    }
                }

                response.Close();                
            }

            this.txbResearch.Text = this.dgrResearch.Items.Count.ToString() + " POPULAR PHRASES AVAILABLE!";            
            this.chbSelAll.IsChecked = dgrResearch.Items.Count > 0? true : false;
            ((LongTailBot.MainWindow)App.Current.MainWindow).PlaySound("abstractbtn.wav");
        }

Answer 1

您应该使用BeginGetResponse方法并将响应处理作为Callback参数传递。然后在“取消”按钮中，调用Abort方法。

没有尝试过，但通常应该可以。

需要帮助添加停止按钮 - ＆gt; HttpWebRequest的

1 个答案: