C＃OleDbConnection Excel設置日期格式

Question

我們使用OleDBConnection將日期導出到Excel工作表，但是每個月的前12天會自動更改為美國格式（MM / dd / yyyy）。

這顯然與我們的數據有關！

我們在整個代碼中都對其進行了檢查，並且我們知道只有在創建文件並插入日期時，它才會被更改。

有沒有一種方法可以強制將日期設置為dd / MM / yyyy格式？

ds.Tables[0].Rows[i][ds.Tables[0].Columns.Count - 1]是日期，格式為dd / MM / yyyy hh：mm：ss

    System.Data.OleDb.OleDbConnection newconn = new System.Data.OleDb.OleDbConnection();
            try
            {
                string pathOfFileToCreate = "U:\\Visual Studio 2013\\Projects\\ANN\\FresnoDataCOC102-2.xlsx";
                newconn.ConnectionString = String.Format(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0 Xml;HDR=YES"";", pathOfFileToCreate);
                newconn.Open();
                var cmd = newconn.CreateCommand();
                cmd.CommandText = "CREATE TABLE sheet1 (Date1 DATETIME, PanEObserved DOUBLE, PanECalculated DOUBLE)";
                cmd.ExecuteNonQuery();
                for (int i = 0; i < training; i++) // Sample Data Insert 
                {
                    int day = Convert.ToInt32(Convert.ToString(ds.Tables[0].Rows[i][ds.Tables[0].Columns.Count - 1]).Substring(0, 2));
                    int month = Convert.ToInt32(Convert.ToString(ds.Tables[0].Rows[i][ds.Tables[0].Columns.Count - 1]).Substring(3, 2));
                    int year = Convert.ToInt32(Convert.ToString(ds.Tables[0].Rows[i][ds.Tables[0].Columns.Count - 1]).Substring(6, 4));
                    DateTime date = new DateTime(year, month, day);

                    cmd.CommandText = String.Format("INSERT INTO Sheet1 (Date1, PanEObserved, PanECalculated) VALUES({0},{1},{2})", "#" + date + "#", ds.Tables[0].Rows[i][inputunits], outputs[i]);
                    cmd.ExecuteNonQuery(); // Execute insert query against excel file.
                }
            }
            finally
            {

                conn.Close();
            }

Answer 1

一個好的解決方法是改用格式化的字符串：

System.Data.OleDb.OleDbConnection newconn = new System.Data.OleDb.OleDbConnection();
        try
        {
            string pathOfFileToCreate = "U:\\Visual Studio 2013\\Projects\\ANN\\FresnoDataCOC102-2.xlsx";
            newconn.ConnectionString = String.Format(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0 Xml;HDR=YES"";", pathOfFileToCreate);
            newconn.Open();
            var cmd = newconn.CreateCommand();
            cmd.CommandText = "CREATE TABLE sheet1 (Date1 String/varhcar(100), PanEObserved DOUBLE, PanECalculated DOUBLE)"; //Check how to declare a varchar exactly.
            cmd.ExecuteNonQuery();
            for (int i = 0; i < training; i++) // Sample Data Insert 
            {
                int day = Convert.ToInt32(Convert.ToString(ds.Tables[0].Rows[i][ds.Tables[0].Columns.Count - 1]).Substring(0, 2));
                int month = Convert.ToInt32(Convert.ToString(ds.Tables[0].Rows[i][ds.Tables[0].Columns.Count - 1]).Substring(3, 2));
                int year = Convert.ToInt32(Convert.ToString(ds.Tables[0].Rows[i][ds.Tables[0].Columns.Count - 1]).Substring(6, 4));
                DateTime date = new DateTime(year, month, day);
                String dateAux = date.ToString("dd/MM/yyyy");
                cmd.CommandText = String.Format("INSERT INTO Sheet1 (Date1, PanEObserved, PanECalculated) VALUES({0},{1},{2})", "#" + dateAux + "#", ds.Tables[0].Rows[i][inputunits], outputs[i]);
                cmd.ExecuteNonQuery(); // Execute insert query against excel file.
            }
        }
        finally
        {

            conn.Close();
        }