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;}