C# 文件上传下载(Excel导入,多线程下载)功能的实现代码

//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;
   }
  }

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();
     }
    }
   }
  }