The code is quite simpke, just have a look.

Add reference to the following dlls:

Interop.Microsoft.Office.Core.dll

Interop.Microsoft.Office.Interop.Excel.dll

Download dlls:

class Program    {        static void Main(string[] args)        {            System.Data.DataTable table = new System.Data.DataTable();            DataColumn column1 = new DataColumn() { ColumnName="Column1"};            DataColumn column2 = new DataColumn() { ColumnName = "Column2" };            table.Columns.Add(column1);            table.Columns.Add(column2);            table.Rows.Add("1","2");            table.Rows.Add("3", "4");            DataTabletoExcel(table, @"C:\temp.XLS");        }        public static void DataTabletoExcel(System.Data.DataTable tmpDataTable, string strFileName)        {            if (tmpDataTable == null)                return;            int rowNum = tmpDataTable.Rows.Count;            int columnNum = tmpDataTable.Columns.Count;            int rowIndex = 1;            int columnIndex = 0;            Application xlApp = new ApplicationClass();            xlApp.DefaultFilePath = "";            xlApp.DisplayAlerts = true;            xlApp.SheetsInNewWorkbook = 1;            Workbook xlBook = xlApp.Workbooks.Add(true);            //将DataTable的列名导入Excel表第一行            foreach (DataColumn dc in tmpDataTable.Columns)            {                columnIndex++;                xlApp.Cells[rowIndex, columnIndex] = dc.ColumnName;            }            //将DataTable中的数据导入Excel中            for (int i = 0; i < rowNum; i++)            {                rowIndex++;                columnIndex = 0;                for (int j = 0; j < columnNum; j++)                {                    columnIndex++;                    xlApp.Cells[rowIndex, columnIndex] = tmpDataTable.Rows[i][j].ToString();                }            }            //xlBook.SaveCopyAs(HttpUtility.UrlDecode(strFileName, System.Text.Encoding.UTF8));            xlBook.SaveCopyAs(strFileName);        }    }

 

Excel to Data:

private static  System.Data.DataTable ExportFromExcelToDataTable()        {            System.Data.DataTable excelDataTable = new System.Data.DataTable();            string excelConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filePath + ";Extended Properties=Excel 12.0";            // Create Connection to Excel Workbook            using (System.Data.OleDb.OleDbConnection excelConnection =                  new System.Data.OleDb.OleDbConnection(excelConnectionString))            {                excelConnection.Open();                System.Data.DataTable dt = excelConnection.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null);                string[] excelSheet = new String[dt.Rows.Count];                int sheet = 0;                foreach (DataRow row in dt.Rows)                {                    excelSheet[sheet] = row["Table_Name"].ToString();                    sheet++;                }                excelDataTable.Clear();                for (int i = 0; i < excelSheet.Length; i++)                {                    System.Data.OleDb.OleDbCommand command = new System.Data.OleDb.OleDbCommand                         ("Select  * FROM [" + excelSheet[i] + "]", excelConnection);                    System.Data.OleDb.OleDbDataAdapter excelAdapter = new System.Data.OleDb.OleDbDataAdapter();                    excelAdapter.SelectCommand = command;                    excelAdapter.Fill(excelDataTable);                }                excelConnection.Close();            }            return excelDataTable;        }