C#实现文件上传下载Excel文档示例代码

public static ReturnValue ReadExcelToDataSet(string xlsFullFileName, bool isHDR, bool isIMEX, int limitSheetCount, bool isOnlyVerify)
{
 ReturnValue returnValue = new ReturnValue();
 string fileExt = UploadFileUtils.GetFileExt(xlsFullFileName);
 if (string.IsNullOrEmpty(fileExt) || !StringUtils.IsInLimitStr("xls,xlsx", fileExt))
 {
  returnValue.HasError = true;
  returnValue.ReturnCode = 1;
  returnValue.Message = "无效excel文件后缀";
  return returnValue;
 }
 if (!File.Exists(xlsFullFileName))
 {
  returnValue.HasError = true;
  returnValue.ReturnCode = 2;
  returnValue.Message = "文件不存在";
  return returnValue;
 }
 StringBuilder stringBuilder = new StringBuilder();
 string str;
 if ("xlsx".Equals(fileExt, StringComparison.CurrentCultureIgnoreCase))
 {
  stringBuilder.Append("Provider=Microsoft.ACE.OLEDB.12.0");
  str = "Excel 12.0;";
 }
 else
 {
  stringBuilder.Append("Provider=Microsoft.Jet.OLEDB.4.0");
  str = "Excel 8.0;";
 }
 stringBuilder.Append(";Data Source=" + xlsFullFileName);
 stringBuilder.Append(";Extended Properties=\"" + str);
 if (isHDR)
 {
  stringBuilder.Append(";HDR=Yes");
 }
 if (isIMEX)
 {
  stringBuilder.Append(";IMEX=1");
 }
 stringBuilder.Append("\"");
 ExcelUtils.log.Debug(stringBuilder.ToString());
 OleDbConnection oleDbConnection = new OleDbConnection(stringBuilder.ToString());
 try
 {
  oleDbConnection.Open();
  DataTable oleDbSchemaTable = oleDbConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[]
  {
   null,
   null,
   null,
   "Table"
  });
  if (oleDbSchemaTable == null || oleDbSchemaTable.Rows.Count == 0)
  {
   returnValue.HasError = true;
   returnValue.ReturnCode = 3;
   returnValue.Message = "读取不到sheet的信息";
   ReturnValue result = returnValue;
   return result;
  }
  if (isOnlyVerify)
  {
   returnValue.HasError = false;
   returnValue.Message = "读取sheet信息正确";
   returnValue.PutValue("dtSheet", oleDbSchemaTable);
   ReturnValue result = returnValue;
   return result;
  }
  int num = oleDbSchemaTable.Rows.Count;
  if (limitSheetCount > 0 && limitSheetCount < oleDbSchemaTable.Rows.Count)
  {
   num = limitSheetCount;
  }
  string[] array = new string[num];
  for (int i = 0; i < num; i++)
  {
   array[i] = oleDbSchemaTable.Rows[i]["TABLE_NAME"].ToString();
  }
  DataSet dataSet = new DataSet();
  for (int j = 0; j < num; j++)
  {
   string text = "select * from [" + array[j] + "]";
   ExcelUtils.log.Debug(text);
   OleDbCommand selectCommand = new OleDbCommand(text, oleDbConnection);
   OleDbDataAdapter oleDbDataAdapter = new OleDbDataAdapter(selectCommand);
   DataTable dataTable = new DataTable(array[j]);
   oleDbDataAdapter.Fill(dataTable);
   dataSet.Tables.Add(dataTable);
  }
  returnValue.HasError = false;
  returnValue.PutValue("dtSheet", oleDbSchemaTable);
  returnValue.PutValue("arrTableName", array);
  returnValue.ReturnObject = dataSet;
  returnValue.Message = "读取成功";
 }
 catch (Exception ex)
 {
  returnValue.HasError = true;
  returnValue.ReturnCode = -100;
  returnValue.ReturnException = ex;
  returnValue.Message = ex.Message;
  ExcelUtils.log.WarnFormat("ReadExcelToDataSet sbConn={0} 出错，原因：{1}", stringBuilder.ToString(), ex.Message);
 }
 finally
 {
  oleDbConnection.Close();
 }
 return returnValue;
}