asp.net WinForm下載檔案並顯示下載進度條教程

WinForm下載檔案並顯示下載進度樣本

代碼如下

複製代碼

/// <summary> /// 顯示進度 /// </summary> /// <param name="val"></param> private void ProgressBar_Value(int val) {     progressBar1.Value = val;     label1.Text = val.ToString() + "%"; } /// <summary> /// 下載檔案 /// </summary> /// <param name="url"></param> /// <param name="savefile"></param> /// <param name="downloadProgressChanged"></param> /// <param name="downloadFileCompleted"></param> private void DownloadFile(string url, string savefile, Action<int> downloadProgressChanged, Action downloadFileCompleted) {     WebClient client = new WebClient();     if (downloadProgressChanged != null)     {         client.DownloadProgressChanged += delegate(object sender, DownloadProgressChangedEventArgs e)         {             this.Invoke(downloadProgressChanged, e.ProgressPercentage);         };     }     if (downloadFileCompleted != null)     {         client.DownloadFileCompleted += delegate(object sender, AsyncCompletedEventArgs e)         {             this.Invoke(downloadFileCompleted);         };     }     client.DownloadFileAsync(new Uri(url), savefile); } delegate void Action(); //.NET Framework 2.0得自訂委託Action /// <summary> /// 點擊下載 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button1_Click(object sender, EventArgs e) {     DownloadFile("http://www.111cn.net/ update.zip", @"F:update.zip", ProgressBar_Value, null); }