将DataGridView导出到Excel而不进行格式更改

Question

我正在创建一个Windows应用程序，我将数据从DataGridView导出到Excel。问题是当它导出数据格式更改时，例如网格中的数据格式为dd/mm/yyyy但是它导出为dd/mm/yyyy tt:mm并且有些像2.10这样的数字会出现在Excel上2.1：

        private void button4_Click(object sender, EventArgs e)
    {
        SaveFileDialog sfd = new SaveFileDialog();
        sfd.Filter = "Excel Documents (*.csv)|*.csv";
        sfd.FileName = "GE.csv";
        if (sfd.ShowDialog() == DialogResult.OK)
        {
            //ToCsV(dataGridView1, @"c:\export.xls");
            ToCsV(dataGridView2, sfd.FileName); // Here dataGridview1 is your grid view name 


        }
        textBox3.Text = sfd.FileName;
        button5.Visible = true;
    }
    private void ToCsV(DataGridView dGV, string filename)
    {
        string stOutput = "";
        // Export titles:
        string sHeaders = "";

        for (int j = 0; j < dGV.Columns.Count; j++)
            sHeaders = sHeaders.ToString() + Convert.ToString(dGV.Columns[j].HeaderText) + "\t";
        stOutput += sHeaders + "\r\n";
        // Export data.
        for (int i = 0; i < dGV.RowCount - 1; i++)
        {
            string stLine = "";
            for (int j = 0; j < dGV.Rows[i].Cells.Count; j++)
                stLine = stLine.ToString() + Convert.ToString(dGV.Rows[i].Cells[j].Value) + "\t";
            stOutput += stLine + "\r\n";
        }
        Encoding utf16 = Encoding.GetEncoding(1254);
        byte[] output = utf16.GetBytes(stOutput);
        FileStream fs = new FileStream(filename, FileMode.Create);
        BinaryWriter bw = new BinaryWriter(fs);
        bw.Write(output, 0, output.Length); //write the encoded file
        bw.Flush();
        bw.Close();
        fs.Close();
    }  

有什么方法吗？

更新：

我已经将数据库上的日期归档更改为varchar并且它有效，但是仍然数字会丢失最后一个decimel如果它为零，我试图将其提取到txt文件它出来的零但是当我打开使用excel的文本会丢失零