废话不多说了，直接给大家贴代码，具体代码如下所示：

//打开Excel文件，转换为DataTable　　　　　 DataTable dtExcel;　　　　private void OpenFile()　　　 {　　　　　　OpenFileDialog dialog = new OpenFileDialog();　　　　　　dialog.Filter = "Microsoft Excel files(*.xls)|*.xls;*.xlsx"; //筛选打开文件类型 ：图片 *.jpg|*.jpg|*.bmp|*.bmp ;"音频文|*.mp3;*.wma;*.aac;*.midi;*.wav" 等等　　　　　　if (dialog.ShowDialog() == DialogResult.OK)　　　　　　{　　　　　　　　dialogFileName = dialog.FileName;　　　　　　　　dtExcel = ExcelToDataTable(dialogFileName, "sheet1", true);　　　　　　}　　　　}/// <summary> /// Excel转Datatable /// </summary> /// <param name="fileName">文件名含后缀名</param> /// <param name="sheetName">Excel文件，页名称</param> /// <param name="isFirstRowColumn">是否将第一列作为表头</param> /// <returns></returns> private DataTable ExcelToDataTable(string fileName, string sheetName, bool isFirstRowColumn) { IWorkbook workbook = null; FileStream fs = null; ISheet sheet = null; DataTable data = new DataTable(); int startRow = 0; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); if (fileName.IndexOf(".xlsx") > 0) // 2007版本 workbook = new XSSFWorkbook(fs); else if (fileName.IndexOf(".xls") > 0) // 2003版本 workbook = new HSSFWorkbook(fs); if (sheetName != null) { sheet = workbook.GetSheet(sheetName); if (sheet == null) //如果没有找到指定的sheetName对应的sheet，则尝试获取第一个sheet { sheet = workbook.GetSheetAt(0); } } else { sheet = workbook.GetSheetAt(0); } if (sheet != null) { IRow firstRow = sheet.GetRow(0); int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数 if (isFirstRowColumn) { for (int i = firstRow.FirstCellNum; i < cellCount; ++i) { ICell cell = firstRow.GetCell(i); if (cell != null) { string cellValue = cell.StringCellValue; if (cellValue != null) { DataColumn column = new DataColumn(cellValue); data.Columns.Add(column); } } } startRow = sheet.FirstRowNum + 1; } else { startRow = sheet.FirstRowNum; } //最后一列的标号 int rowCount = sheet.LastRowNum; for (int i = startRow; i <= rowCount; ++i) { IRow row = sheet.GetRow(i); if (row == null) continue; //没有数据的行默认是null　　　　　　　 DataRow dataRow = data.NewRow(); for (int j = row.FirstCellNum; j < cellCount; ++j) { if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null dataRow[j] = row.GetCell(j).ToString(); } data.Rows.Add(dataRow); } } return data; } catch (Exception ex) { MyMessageBox.Show(ex.Message); return null; } }

文件下载：

private void DownLoad() { if (impdefineBM != null) { FolderBrowserDialog path = new FolderBrowserDialog(); path.ShowDialog(); if (path != null && path.SelectedPath != "") { string url = @"http://192.168.1.1/XX.xls"; //下载地址 string name = "FileName";　　　　　　　　　　　　　　//　文件名称 string savefilepath = path.SelectedPath + "\\" + name + url.Substring(url.LastIndexOf(".")); //注意：下载文件名的命名 ，可根据实际需求调整调用的文件创建方式 MultiDownload download = new MultiDownload(5, url, savefilepath); //调用多线程下载 download.Start(); } } } #region 多线程下载 public class MultiDownload { #region 变量 private int _threadNum; //线程数量 private long _fileSize; //文件大小 private string _fileUrl; //文件地址 private string _fileName; //文件名 private string _savePath; //保存路径 private short _threadCompleteNum; //线程完成数量 private bool _isComplete; //是否完成 private volatile int _downloadSize; //当前下载大小(实时的) private Thread[] _thread; //线程数组 private List<string> _tempFiles = new List<string>(); private object locker = new object(); #endregion #region 属性 /// <summary> /// 文件名 /// </summary> public string FileName { get { return _fileName; } set { _fileName = value; } } /// <summary> /// 文件大小 /// </summary> public long FileSize { get { return _fileSize; } } /// <summary> /// 当前下载大小(实时的) /// </summary> public int DownloadSize { get { return _downloadSize; } } /// <summary> /// 是否完成 /// </summary> public bool IsComplete { get { return _isComplete; } } /// <summary> /// 线程数量 /// </summary> public int ThreadNum { get { return _threadNum; } } /// <summary> /// 保存路径 /// </summary> public string SavePath { get { return _savePath; } set { _savePath = value; } } #endregion /// <summary> /// 构造函数 /// </summary> /// <param name="threahNum">线程数量</param> /// <param name="fileUrl">文件Url路径</param> /// <param name="savePath">本地保存路径</param> public MultiDownload(int threahNum, string fileUrl, string savePath) { this._threadNum = threahNum; this._thread = new Thread[threahNum]; this._fileUrl = fileUrl; this._savePath = savePath; } public void Start() { HttpWebRequest request = (HttpWebRequest)WebRequest.Create(_fileUrl); HttpWebResponse response = (HttpWebResponse)request.GetResponse(); _fileSize = response.ContentLength; int singelNum = (int)(_fileSize / _threadNum); //平均分配 int remainder = (int)(_fileSize % _threadNum); //获取剩余的 request.Abort(); response.Close(); for (int i = 0; i < _threadNum; i++) { List<int> range = new List<int>(); range.Add(i * singelNum); if (remainder != 0 && (_threadNum - 1) == i) //剩余的交给最后一个线程 range.Add(i * singelNum + singelNum + remainder - 1); else range.Add(i * singelNum + singelNum - 1); //下载指定位置的数据 int[] ran = new int[] { range[0], range[1] }; _thread[i] = new Thread(new ParameterizedThreadStart(Download)); _thread[i].Name = System.IO.Path.GetFileNameWithoutExtension(_fileUrl) + "_{0}".Replace("{0}", Convert.ToString(i + 1)); _thread[i].Start(ran); } //MessageBox.Show("下载完成！"); } private void Download(object obj) { Stream httpFileStream = null, localFileStram = null; try { int[] ran = obj as int[]; string tmpFileBlock = System.IO.Path.GetTempPath() + Thread.CurrentThread.Name + ".tmp"; _tempFiles.Add(tmpFileBlock); HttpWebRequest httprequest = (HttpWebRequest)WebRequest.Create(_fileUrl); httprequest.AddRange(ran[0], ran[1]); HttpWebResponse httpresponse = (HttpWebResponse)httprequest.GetResponse(); httpFileStream = httpresponse.GetResponseStream(); localFileStram = new FileStream(tmpFileBlock, FileMode.Create); byte[] by = new byte[5000]; int getByteSize = httpFileStream.Read(by, 0, (int)by.Length); //Read方法将返回读入by变量中的总字节数 while (getByteSize > 0) { Thread.Sleep(20); lock (locker) _downloadSize += getByteSize; localFileStram.Write(by, 0, getByteSize); getByteSize = httpFileStream.Read(by, 0, (int)by.Length); } lock (locker) _threadCompleteNum++; } catch (Exception ex) { throw new Exception(ex.Message.ToString()); } finally { if (httpFileStream != null) httpFileStream.Dispose(); if (localFileStram != null) localFileStram.Dispose(); } if (_threadCompleteNum == _threadNum) { Complete(); _isComplete = true; } } /// <summary> /// 下载完成后合并文件块 /// </summary> private void Complete() { Stream mergeFile = null; BinaryWriter AddWriter = null; try { using (mergeFile = new FileStream(@_savePath, FileMode.Create)) //根据实际情况调整FileMode { AddWriter = new BinaryWriter(mergeFile); foreach (string file in _tempFiles) { using (FileStream fs = new FileStream(file, FileMode.Open)) { BinaryReader TempReader = new BinaryReader(fs); AddWriter.Write(TempReader.ReadBytes((int)fs.Length)); TempReader.Close(); } File.Delete(file); } } MyMessageBox.Show("下载完成！"); } catch (Exception ex) { throw new Exception(ex.Message); } finally { if (AddWriter != null) { AddWriter.Close(); AddWriter.Dispose(); } if (mergeFile != null) { mergeFile.Close(); mergeFile.Dispose(); } } } }

总结

以上所述是小编给大家介绍的C# 文件上传下载(Excel导入,多线程下载)功能的实现代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！