C#下載檔案(可顯示進度)的方法實現
阿新 • • 發佈:2019-02-05
最近在做公司的 進銷存系統,該系統是WINFORM程式,要使用到升級功能,就需要從伺服器上下載最新的軟體程式。如何下載呢?程式碼實現如下:
/// <summary> /// c#,.net 下載檔案 /// </summary> /// <param name="URL">下載檔案地址</param> /// <param name="Filename">下載後的存放地址</param> /// <param name="Prog">用於顯示的進度條</param> public void DownloadFile(string URL, string filename, System.Windows.Forms.ProgressBar prog, System.Windows.Forms.Label label1) { float percent = 0; try { System.Net.HttpWebRequest Myrq = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(URL); System.Net.HttpWebResponse myrp = (System.Net.HttpWebResponse)Myrq.GetResponse(); long totalBytes = myrp.ContentLength; if (prog != null) { prog.Maximum = (int)totalBytes; } System.IO.Stream st = myrp.GetResponseStream(); System.IO.Stream so = new System.IO.FileStream(filename, System.IO.FileMode.Create); long totalDownloadedByte = 0; byte[] by = new byte[1024]; int osize = st.Read(by, 0, (int)by.Length); while (osize > 0) { totalDownloadedByte = osize + totalDownloadedByte; System.Windows.Forms.Application.DoEvents(); so.Write(by, 0, osize); if (prog != null) { prog.Value = (int)totalDownloadedByte; } osize = st.Read(by, 0, (int)by.Length); percent = (float)totalDownloadedByte / (float)totalBytes * 100; label1.Text = "當前補丁下載進度" + percent.ToString() + "%"; System.Windows.Forms.Application.DoEvents(); //必須加註這句程式碼,否則label1將因為迴圈執行太快而來不及顯示資訊 } so.Close(); st.Close(); } catch (System.Exception) { throw; } }