C# Form 在处理信息时卡住

Question

我为自己编写了一个个人网络抓取工具，用于抓取艺术家信息。代码有效，但是当我按下按钮并开始处理 while 循环时，GUI 卡住。我得到了 .refresh() 的文本框。但是我不能移动表格，取消程序的唯一方法是强制退出。我正在重写这个，所以我没有遇到这个问题。另外，我听说了踩踏，想看看它是否可行，并让它更快一点。该程序正在抓取 15,000 多个页面，然后每个页面还有另外 10 个左右的页面需要抓取。因此，该程序可能会运行数小时才能最终完成。

这是我的代码。

        private void btnGet_Click(object sender, EventArgs e)
    {
        int i = 0;
        int maxCount = 15000; //11234 was last value 

        progressBar.Maximum = maxCount;

        while (i <= maxCount)
        {
            txbURL.Text = "http://www.newreleasetuesday.com/albumdetail.php?album_id=" + i;
            label.Text = i.ToString() + " out of " + maxCount.ToString() + " Done.";
            progressBar.Value = i;

            string url = txbURL.Text;

            string sourceCode = sourceCode = WorkerClass.getSourceCode(url);
            int startIndex = sourceCode.IndexOf("//alert(document.getElementById(\"remcheck\").value)");
            sourceCode = sourceCode.Substring(startIndex, sourceCode.Length - startIndex);

            //Start Artist Name
            //Gets the Artist's ID
            int idCountIndex = sourceCode.IndexOf("  by <a href=\"artistdetail.php?artist_id=") + 41;
            int idCountEndIndex = sourceCode.IndexOf("\">", idCountIndex);
            string artistID = sourceCode.Substring(idCountIndex, idCountEndIndex - idCountIndex) + "";
            txbArtistID.Text = artistID;

            //Gets Artist's Name
            startIndex = sourceCode.IndexOf("  by <a href=\"artistdetail.php?artist_id=") + 43 + artistID.Length;
            int endIndex = sourceCode.IndexOf("</a> | Genre", startIndex);
            string artistName = sourceCode.Substring(startIndex, endIndex - startIndex) + "";
            txbArtist.Text = artistName;
            //End Artist Name

            //Start Album Name
            //Gets Album's ID
            string albumID = url.Substring(url.IndexOf("=") + 1);
            txbAlbumID.Text = albumID;

            //Gets Album's Name
            startIndex = sourceCode.IndexOf("absbottom\"></span></strong> ") + 28;
            endIndex = sourceCode.IndexOf("</span></td>", startIndex);
            string AlbumName = sourceCode.Substring(startIndex, endIndex - startIndex) + "";
            txbAlbum.Text = AlbumName;
            //End Album Name

            //Start Genre
            startIndex = sourceCode.IndexOf("</a> | Genre: ") + 14;
            endIndex = sourceCode.IndexOf(" | ", startIndex);
            string genre = sourceCode.Substring(startIndex, endIndex - startIndex) + "";
            txbGenre.Text = genre;
            //End Genre

            //Start Release Date
            startIndex = sourceCode.IndexOf("<a href=\"releasedate.php?release_date=") + 50;
            endIndex = sourceCode.IndexOf(" </a></td>", startIndex);
            string releaseDate = sourceCode.Substring(startIndex, endIndex - startIndex) + "";
            txbReleaseDate.Text = releaseDate;
            //End Release Date

            //Start Pic URL
            startIndex = sourceCode.IndexOf("<img  src=\"") + 11;
            endIndex = sourceCode.IndexOf("\"  alt=", startIndex);
            string PicURL = sourceCode.Substring(startIndex, endIndex - startIndex) + "";
            PicURL = PicURL.Replace("amp;", "");
            string fullLink = "http://www.newreleasetuesday.com/" + PicURL;
            txbPicURL.Text = fullLink;
            //End Pic URL


            //Refresh UI (Updates textBoxes, labels, and progressBar with new values)
            txbURL.Refresh();
            txbArtist.Refresh();
            txbAlbum.Refresh();
            txbReleaseDate.Refresh();
            txbGenre.Refresh();
            txbPicURL.Refresh();
            txbArtistID.Refresh();
            txbAlbumID.Refresh();
            label.Refresh();
            progressBar.Refresh();

            if (artistName == "")
            {
                // Adding info to Database if there is no artist name
                string cs = "SERVER=asdf.net;" +
                    "DATABASE=music;" +
                    "UID=root;" +
                    "PASSWORD=asdf;";

                MySqlConnection conn = null;

                conn = new MySqlConnection(cs);
                conn.Open();

                MySqlCommand cmd = new MySqlCommand();
                cmd.Connection = conn;
                cmd.CommandText = "INSERT INTO `emptyalbums` (id, albumid) VALUES('',@albumid)";
                cmd.Prepare();

                cmd.Parameters.AddWithValue("@albumid", albumID);

                cmd.ExecuteNonQuery();
                conn.Close();
            }
            else
            {
                // Adding info to Database if there is an artist name
                string cs = "SERVER=asdf.net;" +
                    "DATABASE=music;" +
                    "UID=root;" +
                    "PASSWORD=asdf;";

                MySqlConnection conn = null;

                conn = new MySqlConnection(cs);
                conn.Open();

                MySqlCommand cmd = new MySqlCommand();
                cmd.Connection = conn;
                cmd.CommandText = "INSERT INTO `database` (id, artist, album, releasedate, genre, pictureurl, artistid, albumid) VALUES('',@artist, @album, @releasedate, @genre, @pictureurl, @artistid, @albumid)";
                cmd.Prepare();

                cmd.Parameters.AddWithValue("@artist", artistName);
                cmd.Parameters.AddWithValue("@album", AlbumName);
                cmd.Parameters.AddWithValue("@releasedate", releaseDate);
                cmd.Parameters.AddWithValue("@genre", genre);
                cmd.Parameters.AddWithValue("@pictureurl", fullLink);
                cmd.Parameters.AddWithValue("@artistid", artistID);
                cmd.Parameters.AddWithValue("@albumid", albumID);

                cmd.ExecuteNonQuery();
                conn.Close();
            }
            i++;
            
        }

任何信息都会有很长的路要走。谢谢，色氨酸

Answer 1

多线程确实可以解决您的问题。这里发生的是处理在您的 GUI 线程上启动，并且一切都卡住，直到您的循环完成处理。

多线程的实现将取决于您的框架和您的需求，但如果您使用 .Net 4.0，您可能需要查看 TPL 库。

http://msdn.microsoft.com/en-us/library/dd460717.aspx

除此之外，关于多线程的简单谷歌搜索将让您立即到达您想去的地方。