C# HTTP實現斷點續傳客戶端和服務端
一、開篇描述
本篇博客所描述的斷點續傳功能是基于c#語言，服務器端采用.net mvc框架，客戶端采用winform框架。
本篇博客實現斷點續傳功能的基本思路：1）服務器端是把接收到的文件流，追加到已有的文件；2）客戶端是把文件流截段上傳；
其實，任何一種計算機語言基于這個思路（web客戶端JavaScript目前例外），都可以實現斷點續傳的功能。
二、服務器端
namespace MvcApplicationUpload.Controllers { public class HomeController : Controller { /// <summary> /// Index /// </summary> /// <returns></returns> public ActionResult Index() { //string ip = Request.UserHostAddress; //string port = Request.ServerVariables["REMOTE_PORT"].ToString(); return View(); } /// <summary> /// Test /// </summary> /// <returns></returns> public ActionResult Test() { return PartialView(); } /// <summary> /// 獲取續傳點。 /// </summary> /// <param name="md5Name"></param> /// <returns></returns> public string GetFileResumePoint(string md5Name) { var saveFilePath = Server.MapPath("~/Images/") + md5Name; if (System.IO.File.Exists(saveFilePath)) { var fs = System.IO.File.OpenWrite(saveFilePath); var fsLength = fs.Length.ToString(); fs.Close(); return fsLength; } return "0"; } /// <summary> /// 文件續傳。 /// </summary> /// <returns></returns> [HttpPost] public HttpResponseMessage FileResume() { var md5Name = Request.QueryString["md5Name"]; var fileStream = Request.InputStream; var contentRange = Request.Headers["Content-Range"];//contentRange樣例：bytes 0-1000/5000 SaveAs(Server.MapPath("~/Images/") + md5Name, fileStream, contentRange); return new HttpResponseMessage(HttpStatusCode.OK); } /// <summary> /// 給已有文件追加文件流。 /// </summary> /// <param name="saveFilePath"></param> /// <param name="stream"></param> private void SaveAs(string saveFilePath, System.IO.Stream stream, string contentRange) { //接收到的碎片字節流信息。 long startPosition = 0; long endPosition = 0; if (!string.IsNullOrEmpty(contentRange)) { contentRange = contentRange.Replace("bytes", "").Trim(); contentRange = contentRange.Substring(0, contentRange.IndexOf("/")); string[] ranges = contentRange.Split('-'); startPosition = long.Parse(ranges[0]); endPosition = long.Parse(ranges[1]); } else { return; } //默認寫針位置。 System.IO.FileStream fs; long writeStartPosition = 0; if (System.IO.File.Exists(saveFilePath)) { fs = System.IO.File.OpenWrite(saveFilePath); writeStartPosition = fs.Length; } else { fs = new System.IO.FileStream(saveFilePath, System.IO.FileMode.Create); } //調整寫針位置。 if (writeStartPosition >= endPosition) { fs.Close(); return; } else if (writeStartPosition < startPosition) { fs.Close(); return; } else if (writeStartPosition > startPosition && writeStartPosition < endPosition) { writeStartPosition = startPosition; } fs.Seek(writeStartPosition, System.IO.SeekOrigin.Current); //向文件追加文件流。 byte[] nbytes = new byte[512]; int nReadSize = 0; while ((nReadSize = stream.Read(nbytes, 0, 512)) > 0) { fs.Write(nbytes, 0, nReadSize); } fs.Close(); } } }
三、客戶端
1 界面如下：
2 代碼如下：
namespace WindowsFormsApplicationUpload { public partial class Form1 : Form { /// <summary> /// 定義委托。 /// </summary> /// <param name="text"></param> delegate void ChangeText(string text); /// <summary> /// 暫停標記。 /// </summary> int flag = 0; /// <summary> /// 上傳的文件路徑。 /// </summary> string filePath; /// <summary> /// 上傳的文件md5值。 /// </summary> string md5Str; /// <summary> /// 上傳的文件續傳點。 /// </summary> long startPoint; public Form1() { InitializeComponent(); } /// <summary> /// 委托方法。 /// </summary> /// <param name="text"></param> public void ChangeLabelText(string text) { this.label1.Text = text; } /// <summary> /// 得到文件的MD5值。 /// </summary> /// <param name="filePath"></param> /// <returns></returns> public string GetFileMd5(string filePath) { MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider(); FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read); Byte[] hashBytes = md5.ComputeHash(fs); fs.Close(); return BitConverter.ToString(hashBytes).Replace("-", ""); } /// <summary> /// 得到文件的續傳點。 /// </summary> /// <param name="md5Str"></param> /// <param name="fileExtension"></param> /// <returns></returns> public long GetFileResumePoint(string md5Str, string fileExtension) { System.Net.WebClient webClient = new System.Net.WebClient(); string urlStr = "http://127.0.0.1/Home/GetFileResumePoint?md5Name=" + md5Str + fileExtension; byte[] infoBytes = webClient.DownloadData(urlStr); string result = System.Text.Encoding.UTF8.GetString(infoBytes); webClient.Dispose(); if (string.IsNullOrEmpty(result)) { return 0; } return Convert.ToInt64(result); } public void ResumeFileThread() { MessageBox.Show(ResumeFile("http://127.0.0.1/Home/FileResume", filePath, startPoint, 1024 * 128, md5Str)); } public string ResumeFile(string hostUrl, string filePath, long startPoint, int byteCount, string md5Str) { string result = "上傳成功！"; if (startPoint < 0) { result = "指針有誤！"; return result; } FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read); long fileLength = fs.Length; if (startPoint >= fileLength) { result = "文件秒傳！"; return result; } byte[] data; System.Net.WebClient webClient = new System.Net.WebClient(); BinaryReader bReader = new BinaryReader(fs); try { #region 續傳處理 if (startPoint >= 1 && startPoint < fileLength) { fs.Seek(startPoint, SeekOrigin.Current); } #endregion #region 分割文件上傳 int step = byteCount; for (; startPoint < fileLength; startPoint += step) { if (startPoint + byteCount > fileLength) { step = Convert.ToInt32(fileLength - startPoint); data = new byte[step]; bReader.Read(data, 0, step); } else { data = new byte[byteCount]; bReader.Read(data, 0, byteCount); } webClient.Headers.Set(HttpRequestHeader.ContentRange, "bytes " + startPoint + "-" + (startPoint + step) + "/" + fs.Length); webClient.UploadData(hostUrl + "?md5Name=" + md5Str + Path.GetExtension(filePath), "POST", data); this.BeginInvoke(new ChangeText(ChangeLabelText), (startPoint + step) + "/" + fileLength); pause: if (flag == 1) { Thread.Sleep(1000); goto pause; } } #endregion } catch (Exception ex) { result = ex.Message; } finally { bReader.Close(); fs.Close(); webClient.Dispose(); } return result; } /// <summary> /// 上傳按鈕點擊事件。 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button1_Click(object sender, EventArgs e) { OpenFileDialog openFileDialog = new OpenFileDialog(); if (openFileDialog.ShowDialog() == DialogResult.OK) { filePath = openFileDialog.FileName; md5Str = GetFileMd5(filePath); startPoint = GetFileResumePoint(md5Str, Path.GetExtension(filePath)); ThreadStart ts = new ThreadStart(ResumeFileThread); Thread t = new Thread(ts); t.Start(); } } /// <summary> /// 暫停按鈕點擊事件。 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button2_Click(object sender, EventArgs e) { flag = 1; } /// <summary> /// 繼續按鈕點擊事件。 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button3_Click(object sender, EventArgs e) { flag = 0; } /// <summary> /// 拖拽上傳。 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void Form1_Drag(object sender, DragEventArgs e) { if (e.Data.GetDataPresent(DataFormats.FileDrop)) { string[] files = e.Data.GetData(DataFormats.FileDrop) as string[]; MessageBox.Show("準備上傳" + files.Length + "個文件！"); foreach (string file in files) { MessageBox.Show("開始上傳文件：" + file); filePath = file; md5Str = GetFileMd5(filePath); startPoint = GetFileResumePoint(md5Str, Path.GetExtension(filePath)); ThreadStart ts = new ThreadStart(ResumeFileThread); Thread t = new Thread(ts); t.Start(); } } } private void Form1_DragDrop(object sender, DragEventArgs e) { //Form1_Drag(sender, e); } private void Form1_DragOver(object sender, DragEventArgs e) { Form1_Drag(sender, e); } } }
來源:https://blog.csdn.net/qq_18932003/article/details/120521365
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