格式化日期字符串

第一种是我以前常用的，但比较麻烦(后面还有更简洁的)：

    /// <summary>
    /// 格式化日期字符串
    /// </summary>
    /// <param name="dt"></param>
    /// <param name="type"></param>
    /// <returns></returns>
    private string DateDiff(string dt, int type)
    {
        string time = dt;
        try
        {
            DateTime t = Convert.ToDateTime(dt);
            string year = t.Year.ToString();
            string month = t.Month.ToString("00");
            string day = t.Day.ToString("00");
            string hour = t.Hour.ToString("00");
            string minute = t.Minute.ToString("00");

            switch (type)
            {
                case 1:
                    time = string.Format("{0}-{1}-{2} {3}:{4}", year, month, day, hour, minute);
                    break;
                case 2:
                    time = string.Format("{0}-{1}-{2}", year, month, day);
                    break;
                default:
                    time = string.Format("{0}-{1}-{2}", year, month, day);
                    break;
            }
        }
        catch (Exception)
        {

        }
        return time;
    }

上面这种比较麻烦，下面有种更简洁的办法：

    /// <summary>
    /// 返回日期格式化字符串
    /// </summary>
    /// <param name="dt"></param>
    /// <param name="type"></param>
    /// <returns></returns>
    private string Datediff(string dt, int type)
    {
        string t = dt;
        try
        {
            DateTime date = Convert.ToDateTime(dt);
            switch (type)
            {
                case 1:
                    t = date.ToString("yyyy-MM-dd HH:mm");
                    break;
                case 2:
                    t = date.ToString("yyyy-MM-dd");
                    break;
                default:
                    t = date.ToString("yyyy-MM-dd");
                    break;
            }
        }
        catch (Exception)
        {

        }
        return t;
    }

调用的办法很简单，如下：

        string sql = "SELECT * FROM HR_ProductBOMList_V " + condition + " ORDER BY [FormNo] DESC";

        gvExcel.DataSource = DbHelperSQL.Query(sql);

        gvExcel.DataBind();

        int nCount = gvExcel.Rows.Count;
        string createTime,dt;
        for (int i = 0; i < nCount; i++)
        {
            dt = gvExcel.Rows[i].Cells[9].Text;

            gvExcel.Rows[i].Cells[9].Text = Datediff(dt, 1);
        }