Excel中导数据到DataGridView中

最近项目中需要从Excel中导数据到DataGridView中，所以写了一个通用类,代码如下：

 1 public   class  ExcelToDatableHelper  2      { 3        private static ExcelToDatableHelper instance = null; 4        private static Object locker = new Object(); 5 6        public static ExcelToDatableHelper Instance 7        { 8            get 9            {10                if (instance == null)11                {12                    lock (locker)13                    {14                        if (instance == null)15                        {16                            instance = new ExcelToDatableHelper();17                        }18                    }19                }20                return instance;21            }22        }2324        /**//// <summary>25        /// Reads the excel.26        /// </summary>27        /// <param name="strFileName">Name of the file.</param>28        /// <param name="sheetName">Name of the sheet.</param>29        /// <param name="colName">Name of the col.</param>30        /// <returns></returns>31        public DataSet ReadExcel(string strFileName, string sheetName, List<string> colName)32        {33            string strConnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source = " + strFileName + ";Extended Properties = Excel 8.0";34            OleDbConnection oleConnection = new OleDbConnection(strConnection);35            StringBuilder strColName = new StringBuilder("");36            string myStrColName = "";37            if (colName.Count > 0)38            {39                foreach (string str in colName)40                {41                    strColName.Append(str);42                    strColName.Append(",");43                }44                myStrColName = strColName.ToString().Substring(0, strColName.Length - 1);  // 去掉","45            }46            try47            {48                oleConnection.Open();49                DataSet dsRead = new DataSet();50                OleDbDataAdapter oleAdper = new OleDbDataAdapter(" SELECT " + myStrColName + "  FROM [" + sheetName + "$]", oleConnection);51                oleAdper.Fill(dsRead, "result");52                return dsRead;53            }54            catch (Exception ex)55            {56                MessageBox.Show(ex.ToString());57                return null;58            }59            finally60            {61                oleConnection.Close();62            }63        }6465        /**//// <summary>66        /// Opens the file.67        /// </summary>68        /// <returns></returns>69        public string OpenFile()70        {71            OpenFileDialog openFileDialog = new OpenFileDialog();72            openFileDialog.InitialDirectory = Application.StartupPath;73            //openFileDialog.Filter="文本文件|*.*|Excel文件|*.xls|C#文件|*.cs|所有文件|*.*"; 74            openFileDialog.Filter = "Excel文件|*.xls";75            openFileDialog.RestoreDirectory = true;76            openFileDialog.Title = "打开文件";77            openFileDialog.FilterIndex = 1;78            if (openFileDialog.ShowDialog() == DialogResult.OK)79            {80                return (openFileDialog.FileName);81            }82            else return String.Empty;83        }84    }