Question

在构造函数

中

public Form1()
        {
            InitializeComponent();

            label2.Visible = false;
            label3.Visible = false;
            label4.Visible = false;
            label7.Visible = false;

            tbxMainDownloadPath.Text = Properties.Settings.Default.LastSelectedFolder;
            if (tbxMainDownloadPath.Text != "")
                downloadDirectory = tbxMainDownloadPath.Text;

            tracker = new DownloadProgressTracker.DownloadProgress(50, TimeSpan.FromMilliseconds(500));
            string[] countries = File.ReadAllLines(@"CountriesNames.txt");
            string[] countriesCodes = File.ReadAllLines(@"CountriesCodes.txt");
            foreach (string country in countries)
            {
                countryList.Add(country);
                string countryPath = Path.Combine(downloadDirectory, country);
                if (!Directory.Exists(countryPath))
                    Directory.CreateDirectory(countryPath);
            }
            foreach (string code in countriesCodes)
            {
                codesList.Add(code);
            }
            codeToFullNameMap = codesList
                .Select((code, index) => index)
                .ToDictionary(
                              keySelector: index => codesList[index],
                              elementSelector: index => countryList[index]);

            lines = File.ReadAllLines(@"links.txt");

            for (int i = 0; i < lines.Length; i++)
            {
                RichTextBoxExtensions.AppendText(true, richTextBox1, "Ready: ", Color.Red, 8.25f);
                richTextBox1.AppendText(lines[i] + (i < lines.Length - 1 ? Environment.NewLine : String.Empty));
            }

            for (int i = 0; i < countriesCodes.Length; i++)
            {
                dataGridView1.ColumnCount = 2;
                dataGridView1.Columns[0].Name = "Status";
                dataGridView1.Columns[1].Name = "Country";
                var countryName = codeToFullNameMap[countriesCodes[i]];
                string[] row = new string[] { "Ready", countryName };
                dataGridView1.Rows.Add(row);
                DataGridViewLinkColumn dgvLink = new DataGridViewLinkColumn();
                dgvLink.UseColumnTextForLinkValue = true;
                dgvLink.LinkBehavior = LinkBehavior.SystemDefault;
                dgvLink.HeaderText = "Link Data";
                dgvLink.Name = "SiteName";
                dgvLink.LinkColor = Color.Blue;
                dgvLink.TrackVisitedState = true;
                dgvLink.Text = lines[i];
                dgvLink.UseColumnTextForLinkValue = true;
                dataGridView1.Columns.Add(dgvLink);
            }
            this.dataGridView1.Columns[2].AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;

            DataGridViewCellStyle mystyle = new DataGridViewCellStyle();
            mystyle.SelectionBackColor = Color.White;
            mystyle.SelectionForeColor = Color.Red;
            dataGridView1.DefaultCellStyle = mystyle;

            dataGridView1.RowHeadersVisible = false;
            dataGridView1.AllowUserToAddRows = false;
            dataGridView1.BackgroundColor = System.Drawing.SystemColors.Control;

            dataGridView1.Columns[0].DefaultCellStyle.ForeColor = Color.Red;
        }

运行程序时

然后在第一个文件下载完成时开始下载我将状态从Ready in Red更改为Downloaded in Green：

private void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                // handle error scenario
                throw e.Error;
            }
            if (e.Cancelled)
            {
                // handle cancelled scenario
            }

            if (url.Contains("animated") && url.Contains("infra"))
            {
                Image img = new Bitmap(lastDownloadedFile);
                Image[] frames = GetFramesFromAnimatedGIF(img);
                foreach (Image image in frames)
                {
                    countFrames++;
                    image.Save(downloadDirectory + "\\" + fname + ".gif");
                }
            }

            RichTextBoxExtensions.UpdateText(richTextBox1, "Ready: ", "Downloaded: ", Color.Green);
            label2.Text = "Download Complete";

                DataGridViewRow row = new DataGridViewRow();
            dataGridView1.Rows[0].Cells[0].Value = "Downloaded";
            dataGridView1.Rows[0].Cells[0].Style.SelectionForeColor = Color.Green;
            tracker.NewFile();
            DownloadFile();
        }

下载文件后

问题是它总是单元格[0] 如何找到已下载的链接/文件并将单元格值更改为正确的索引？

例如，如果已完成的事件中存在错误，我想将正确的单元格索引值更改为红色的“错误”。如果下载的文件没有任何问题，请将正确的单元格索引更改为绿色的“已下载”。

问题是如何找到正确的细胞指数？

我注册已完成事件的方法。我通过按钮点击事件调用此方法。

private void DownloadFile()
        {
            if (_downloadUrls.Any())
            {
                WebClient client = new WebClient();
                client.DownloadProgressChanged += client_DownloadProgressChanged;
                client.DownloadFileCompleted += client_DownloadFileCompleted;

                url = _downloadUrls.Dequeue();

                if (url.Contains("animated") && url.Contains("infra"))
                {
                    string startTag = "animated/";
                    string endTag = "/infra";

                    int index = url.IndexOf(startTag);
                    int index1 = url.IndexOf(endTag);

                    fname = url.Substring(index + 9, index1 - index - 9);
                    var countryName = codeToFullNameMap[fname];
                    downloadDirectory = tbxMainDownloadPath.Text;
                    downloadDirectory = Path.Combine(downloadDirectory, countryName);
                }
                else
                {
                    fname = "Tempfile";
                    downloadDirectory = tbxMainDownloadPath.Text;
                }

                client.DownloadFileAsync(new Uri(url), downloadDirectory + "\\" + fname + ".gif");
                lastDownloadedFile = downloadDirectory + "\\" + fname + ".gif";

                return;
            }

            // End of the download
            label2.Text = "All files have been downloaded";
        }

最后一次progresschanged事件

void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {
            tracker.SetProgress(e.BytesReceived, e.TotalBytesToReceive);
            pBarFileProgress.Value = (int)(tracker.GetProgress() * 100.0);
            label3.Text = e.BytesReceived + "/" + e.TotalBytesToReceive;
            label7.Text = tracker.GetBytesPerSecondString();
            label2.Text = "Downloading";
            label4.Text = downloadDirectory + "\\" + fname + ".gif";
        }

将url添加到队列的downloadfile方法

private void downloadFile(IEnumerable<string> urls)
        {
            foreach (var url in urls)
            {
                _downloadUrls.Enqueue(url);
            }

            // Starts the download
            btnStart.Text = "Downloading...";
            btnStart.Enabled = false;
            pBarFileProgress.Visible = true;

            DownloadFile();

            label2.Visible = true;
            label3.Visible = true;
            label4.Visible = true;
            label7.Visible = true;
            label3.Text = "";
            label7.Text = "";
            label2.Text = "";
            label4.Text = "";
        }

Answer 1

代码中存在多个问题。我只关注与你的问题相关的问题。此外，我尽可能保留您自己的代码，以便您可以更好地理解代码和建议代码之间的区别

您应该在构造函数中仅设置一次网格，然后将所需的行数据添加到其中。目前，您正在重复设置列 - 这就是使DataGridViewLinkColumn工作的原因。

您的代码：

for (int i = 0; i < countriesCodes.Length; i++)
{
    dataGridView1.ColumnCount = 2;
    dataGridView1.Columns[0].Name = "Status";
    dataGridView1.Columns[1].Name = "Country";
    var countryName = codeToFullNameMap[countriesCodes[i]];
    string[] row = new string[] { "Ready", countryName };
    dataGridView1.Rows.Add(row);
    DataGridViewLinkColumn dgvLink = new DataGridViewLinkColumn();
    dgvLink.UseColumnTextForLinkValue = true;
    dgvLink.LinkBehavior = LinkBehavior.SystemDefault;
    dgvLink.HeaderText = "Link Data";
    dgvLink.Name = "SiteName";
    dgvLink.LinkColor = Color.Blue;
    dgvLink.TrackVisitedState = true;
    dgvLink.Text = lines[i];
    dgvLink.UseColumnTextForLinkValue = true;
    dataGridView1.Columns.Add(dgvLink);
}

更好且更正的代码：

dataGridView1.ColumnCount = 2;
dataGridView1.Columns[0].Name = "Status";
dataGridView1.Columns[1].Name = "Country";

DataGridViewLinkColumn dgvLink = new DataGridViewLinkColumn();
dgvLink.UseColumnTextForLinkValue = true;
dgvLink.LinkBehavior = LinkBehavior.SystemDefault;
dgvLink.HeaderText = "Link Data";
dgvLink.Name = "SiteName";
dgvLink.LinkColor = Color.Blue;
dgvLink.TrackVisitedState = true;
dgvLink.UseColumnTextForLinkValue = false;
dataGridView1.Columns.Add(dgvLink);
dataGridView1.Columns[2].AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;

for (int i = 0; i < countriesCodes.Length; i++) {
    var countryName = codeToFullNameMap[countriesCodes[i]];
    string[] row = new string[] { "Ready", countryName, lines[i] };
    dataGridView1.Rows.Add(row);
}

在client_DownloadFileCompleted函数中，您应该使用我的代码替换代码

您的代码：

DataGridViewRow row = new DataGridViewRow();
dataGridView1.Rows[0].Cells[0].Value = 
dataGridView1.Rows[0].Cells[0].Style.SelectionForeColor = Color.Green;

更正后的代码：

var row = dataGridView1.Rows.Cast<DataGridViewRow>()
            .First(r => r.Cells[2].Value.Equals(url));
row.Cells[0].Value = "Downloaded";
row.Cells[0].Style.ForeColor = Color.Green;

这可以让你获得理想的行为。如您所见，变量row应该具有与url对应的正确行。您可以根据需要更改所需的单元格文本和样式 - 处理错误情况以及成功下载案例

如何根据下载的文件更改datagridview单元格文本？

1 个答案: