c# excel 파일 읽기

excel 파일 읽기

   public DataSet getData()
        {
            // 
            OpenFileDialog file = new OpenFileDialog();
            file.Filter = "Excel(*.xlsx)|*.xlsx|Excel(*.xls)|*.xls";
            file.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
            file.Multiselect = false;
            if (file.ShowDialog() == DialogResult.Cancel)
                return null;
            // 
            var path = file.FileName;
            string fileSuffix = System.IO.Path.GetExtension(path);
            if (string.IsNullOrEmpty(fileSuffix))
                return null;
            using (DataSet ds = new DataSet())
            {
                // Excel 2003 2007 
                string connString = "";
                if (fileSuffix == ".xls")
                    connString = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + path + ";" + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\"";
               else
                    connString = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + path + ";" + ";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"";
                // 
                string sql_select = " SELECT * FROM [Sheet1$]";
                using (OleDbConnection conn = new OleDbConnection(connString))
                using (OleDbDataAdapter cmd = new OleDbDataAdapter(sql_select, conn))
                {
                    conn.Open();
                    cmd.Fill(ds);
                }
                if (ds == null || ds.Tables.Count <= 0) return null;
                return ds;
            }
        }