Question

我有datagridview并使用这些代码在数据库中更新。但我在datagridview中更新日期时遇到问题我的列日期是（ra8，ra9）我尝试更新时会出现这些错误

从字符串转换日期和/或时间时转换失败。

private void button1_Click(object sender, EventArgs e)
        {

            con = new SqlConnection(cs.DBConn);


            foreach (DataGridViewRow dgRow in dgw.Rows)
            {
                string Id = dgRow.Cells[0].Value.ToString();
                string Id2 = dgRow.Cells[1].Value.ToString();
                string isEdit2 = dgRow.Cells[2].Value.ToString();
                string isEdit = dgRow.Cells[3].Value.ToString();
                string isDelete = dgRow.Cells[4].Value.ToString();
                string isADD = dgRow.Cells[5].Value.ToString();
                string isADD1 = dgRow.Cells[6].Value.ToString();
                string isADD2 = dgRow.Cells[7].Value.ToString();
                string isADD3 = dgRow.Cells[8].Value.ToString();
                DateTime isADD4 =Convert.ToDateTime( dgRow.Cells[9].Value.ToString());
                DateTime isADD5 =Convert.ToDateTime( dgRow.Cells[10].Value.ToString());    
                string isADD6 = dgRow.Cells[11].Value.ToString();

                string cb = "update ma3 set ra1='" + Id2 + "',  ra2='" + isEdit2 + "', ra3='" + isEdit + "', ra4='" + isDelete + "', ra5='" + isADD + "', ra6='" + isADD1 + "', ra7='" + isADD2 + "', ra8='" + isADD3 + "', ra9='" + isADD4 + "', ra10='" + isADD5 + "', ra11='" + isADD6 + "' where id='" + Id + "'";
                con.Open();
                cmd = new SqlCommand(cb);
                cmd.Connection = con;
                cmd.ExecuteReader();
                con.Close();

            }                
        }

Answer 1

不要使用Convert.ToDateTime，请使用DateTime.TryParseExact;并将字符串转换为日期时间。

使用TryParseExact与您的合成器一起工作，这样您的程序就不会因异常而失败，而是可以通过bool值安全地检查转换是否完成

 string datestr = "26/12/2017 12:00:00 am";

    DateTime test = DateTime.Now;

   if( DateTime.TryParseExact(datestr, "dd/MM/yyyy hh:mm:ss tt", null,
                    System.Globalization.DateTimeStyles.None, out test))
    {
         //insert in db or proceed with input
    }
    else
    {
      //log and provide error message 
     }

Answer 2

      private void button1_Click(object sender, EventArgs e)
             {  con = new SqlConnection(cs.DBConn);

                 foreach (DataGridViewRow dgRow in dgw.Rows)
                {
                     string id = dgRow.Cells[0].Value.ToString(); 
                     string date = dgRow.Cells[1].Value.ToString();
                     DateTime  test;
                     string cb = "update date set date='" + DateTime.TryParseExact(date, "dd/MM/yyyy",
    CultureInfo.InvariantCulture, DateTimeStyles.None, out test) +  "' where id='" + id + "'";

                   con.Open();
                    cmd = new SqlCommand(cb);
                    cmd.Connection = con;
                   cmd.ExecuteReader();
                  con.Close();

             } 
}

好的，我尝试这些代码，这些消息显示正常转换失败时从字符串转换日期和/或时间。

更新datagridview中的日期格式时出现错误

2 个答案: