C# 通过 oledb 操作Excel

public string GetConnectionString()
        {
            Dictionary<string, string> props = new Dictionary<string, string>();

            // XLSX - Excel 2007, 2010, 2012, 2013
            props["Provider"] = "Microsoft.ACE.OLEDB.12.0;";
            props["Extended Properties"] = "Excel 12.0 XML";
            props["Data Source"] = @"C:\tools\MyExcel.xlsx";

            // XLS - Excel 2003 and Older
            //props["Provider"] = "Microsoft.Jet.OLEDB.4.0";
            //props["Extended Properties"] = "Excel 8.0";
            //props["Data Source"] = "C:\\MyExcel.xls";

            var sb = new StringBuilder();

            foreach (KeyValuePair<string, string> prop in props)
            {
                sb.Append(prop.Key);
                sb.Append('=');
                sb.Append(prop.Value);
                sb.Append(';');
            }

            return sb.ToString();
        }

        public void WriteExcelFile()
        {
            string connectionString = GetConnectionString();

            using (OleDbConnection conn = new OleDbConnection(connectionString))
            {
                conn.Open();
                OleDbCommand cmd = new OleDbCommand();
                cmd.Connection = conn;

                cmd.CommandText = "CREATE TABLE [table1] (id INT, name VARCHAR, datecol DATE );";
                cmd.ExecuteNonQuery();

                cmd.CommandText = "INSERT INTO [table1](id,name,datecol) VALUES(1,'AAAA','2014-01-01');";
                cmd.ExecuteNonQuery();

                cmd.CommandText = "INSERT INTO [table1](id,name,datecol) VALUES(2, 'BBBB','2014-01-03');";
                cmd.ExecuteNonQuery();

                cmd.CommandText = "INSERT INTO [table1](id,name,datecol) VALUES(3, 'CCCC','2014-01-03');";
                cmd.ExecuteNonQuery();

                cmd.CommandText = "UPDATE [table1] SET name = 'DDDD' WHERE id = 3;";
                cmd.ExecuteNonQuery();

                conn.Close();
            }
        }

        public DataSet ReadExcelFile()
        {
            DataSet ds = new DataSet();

            string connectionString = GetConnectionString();

            using (OleDbConnection conn = new OleDbConnection(connectionString))
            {
                conn.Open();
                OleDbCommand cmd = new OleDbCommand();
                cmd.Connection = conn;

                // Get all Sheets in Excel File
                DataTable dtSheet = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

                // Loop through all Sheets to get data
                foreach (DataRow dr in dtSheet.Rows)
                {
                    string sheetName = dr["TABLE_NAME"].ToString();

                    if (!sheetName.EndsWith("$"))
                        continue;

                    // Get all rows from the Sheet
                    cmd.CommandText = "SELECT * FROM [" + sheetName + "]";

                    DataTable dt = new DataTable();
                    dt.TableName = sheetName;

                    OleDbDataAdapter da = new OleDbDataAdapter(cmd);
                    da.Fill(dt);

                    ds.Tables.Add(dt);
                }

                cmd = null;
                conn.Close();
            }

            return ds;
        }