C# 读取excel数据到datatable

     在项目中使用到遇到了需要将excel文件导入到数据库中，在此做个总结记录，防止后面人踩坑。

    开发环境：VS2008+Win10

第一种方式：Office.Interop.Excel方式  数据量大时有点慢

        public static DataTable getExcelDataKHFY(string fileName, DataTable dt)
        {
            string[] names = GetExcelTableName(fileName);
            int ysCount = 0;//获取页数
            string exname = "";
            if (names.Length > 1)
            {
                Yx_Module.winChangeExcel win = new THKClient.Yx_Module.winChangeExcel(names);

                win.ShowDialog();
                if (win.IsReturn)
                {
                    ysCount = int.Parse(win.Excelid) + 1;//页码
                    exname = win.ExName;//选择的页名
                }

            }

            DataTable result = dt;
            Microsoft.Office.Interop.Excel.Application xlApp = null;
            Microsoft.Office.Interop.Excel.Workbook xlWorkbook = null;
            try
            {
                xlApp = new Microsoft.Office.Interop.Excel.Application();
                if (xlApp == null) return null;

                xlApp.Visible = false;
                xlWorkbook = xlApp.Workbooks.Open(fileName, 0, false, 5, "", "", false, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "", true, false, 0, true, false, false);
                Dictionary<int, Microsoft.Office.Interop.Excel.Range> rowrange = new Dictionary<int, Microsoft.Office.Interop.Excel.Range>();
                if (ysCount != 0)
                {
                    try
                    {
                        //动态页插入数据
                        int i = ysCount;
                        // Microsoft.Office.Interop.Excel.Worksheet sheet = (Microsoft.Office.Interop.Excel.Worksheet)xlWorkbook.Sheets[i];//根据页码
                        Microsoft.Office.Interop.Excel.Worksheet sheet = (Microsoft.Office.Interop.Excel.Worksheet)xlWorkbook.Sheets[exname];//根据页名获取
                        string str = sheet.Name;
                        for (int rowIndex = 2; rowIndex < sheet.Cells.Rows.Count - 1; rowIndex++)
                        {
                            rowrange.Clear();
                            object[] parm = new object[result.Columns.Count];
                            for (int j = 0; j < result.Columns.Count; j++)
                            {
                                rowrange[j] = (Microsoft.Office.Interop.Excel.Range)(sheet.Cells[rowIndex, j + 1]);

                                parm[j] = rowrange[j].Value2 == null ? "" : rowrange[j].Value2.ToString();
                            }



                            rowrange.Clear();
                            if (parm[0].ToString().Trim().Length == 0)
                            {
                                break;
                            }
                            result.Rows.Add(parm);
                        }
                    }
                    catch (Exception ee)
                    {

                        throw;
                    }
                }
                else
                {
                    for (int i = 1; i < xlWorkbook.Sheets.Count + 1; i++)
                    {
                        Microsoft.Office.Interop.Excel.Worksheet sheet = (Microsoft.Office.Interop.Excel.Worksheet)xlWorkbook.Sheets[i];
                        string str = sheet.Name;
                        for (int rowIndex = 2; rowIndex < sheet.Cells.Rows.Count - 1; rowIndex++)
                        {
                            rowrange.Clear();
                            object[] parm = new object[result.Columns.Count];
                            for (int j = 0; j < result.Columns.Count; j++)
                            {
                                rowrange[j] = (Microsoft.Office.Interop.Excel.Range)(sheet.Cells[rowIndex, j + 1]);

                                parm[j] = rowrange[j].Value2 == null ? "" : rowrange[j].Value2.ToString();
                            }



                            rowrange.Clear();
                            if (parm[0].ToString().Trim().Length == 0)
                            {
                                break;
                            }
                            result.Rows.Add(parm);
                        }
                    }
                }

                xlWorkbook.Close(Type.Missing, Type.Missing, Type.Missing);
                xlApp.Quit();
            }
            finally
            {
                Marshal.ReleaseComObject(xlWorkbook);
                Marshal.ReleaseComObject(xlApp);
                xlApp = null;
                List<Process> excelProcesses = GetExcelProcesses();
                if (excelProcesses.Count > 0)
                {
                    KillTheExcel();//杀死进程

                }
            }

            return result;
        }

第二种方式：NPOI方式  此种方式最优 

        /// <summary>读取excel
        /// 默认第一行为表头
        /// </summary>
        /// <param name="strFileName">excel文档路径</param>
        /// <returns></returns>
        public static DataTable Import(string strFileName)
        {
            DataTable dt = new DataTable();

            HSSFWorkbook hssfworkbook;
            using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))
            {
                hssfworkbook = new HSSFWorkbook(file);
            }
            HSSFSheet sheet = hssfworkbook.GetSheetAt(0);
            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

            HSSFRow headerRow = sheet.GetRow(0);
            int cellCount = headerRow.LastCellNum;

            for (int j = 0; j < cellCount; j++)
            {
                HSSFCell cell = headerRow.GetCell(j);
                dt.Columns.Add(cell.ToString());
            }

            for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
            {
                HSSFRow row = sheet.GetRow(i);
                DataRow dataRow = dt.NewRow();

                for (int j = row.FirstCellNum; j < cellCount; j++)
                {
                    if (row.GetCell(j) != null)
                        dataRow[j] = row.GetCell(j).ToString();
                }

                dt.Rows.Add(dataRow);
            }
            return dt;
        }

第三种方式：OLEDB方式  需要将程序设置为X86运行

public static DataTable ExcelToDataTable(string filePath)
        {
            string connStr = "";
            string fileType = System.IO.Path.GetExtension(filePath);
            if (string.IsNullOrEmpty(fileType)) return null;

            if (fileType == ".xls")
                connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + filePath + ";" + ";Extended Properties="Excel 8.0;HDR=YES;IMEX=1"";
            else
                connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + filePath + ";" + ";Extended Properties="Excel 12.0;HDR=YES;IMEX=1"";
            string sql_F = "Select * FROM [{0}]";

            DataSet ds = new DataSet();

            //using (OleDbConnection myConn = new OleDbConnection(connStr))
            //{
            //    using (OleDbDataAdapter myCommand = new OleDbDataAdapter(sql_F, myConn))
            //    {
            //        myConn.Open();
            //        myCommand.Fill(ds);
            //    }
            //}

            //if (ds == null || ds.Tables.Count <= 0) return null;
            //return ds.Tables[0];


            OleDbConnection conn = null;
            OleDbDataAdapter da = null;
            DataTable dtSheetName = null;
            try
            {
                // 初始化连接，并打开
                conn = new OleDbConnection(connStr);
                conn.Open();

                // 获取数据源的表定义元数据                        
                string SheetName = "";
                dtSheetName = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

                // 初始化适配器
                da = new OleDbDataAdapter();
                for (int i = 0; i < dtSheetName.Rows.Count; i++)
                {
                    SheetName = (string)dtSheetName.Rows[i]["TABLE_NAME"];

                    if (SheetName.Contains("$") && !SheetName.Replace("'", "").EndsWith("$"))
                    {
                        continue;
                    }

                    da.SelectCommand = new OleDbCommand(String.Format(sql_F, SheetName), conn);
                    DataSet dsItem = new DataSet();
                    da.Fill(dsItem);

                    ds.Tables.Add(dsItem.Tables[0].Copy());
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {
                // 关闭连接
                if (conn.State == ConnectionState.Open)
                {
                    conn.Close();
                    da.Dispose();
                    conn.Dispose();
                }
            }
            return ds.Tables[0];
        }