无法在asp.net中编辑文本框

Question

我在page_load上运行了以下代码

 using (SqlConnection conn = new SqlConnection("myconnectionString"))
        {
            conn.Open();
            using (SqlCommand cmmnd = new SqlCommand("", conn))
            {



                cmmnd.CommandText = "SELECT * FROM addsetting;";


                SqlDataReader rdr = cmmnd.ExecuteReader();
                while (rdr.Read())
                {
                    count++;
                    param = Convert.ToString(rdr["rowno"]);
                    TextBox1.Text = Convert.ToString(rdr["tostudent"]);
                    TextBox2.Text = Convert.ToString(rdr["tofaculty"]);
                    TextBox3.Text = Convert.ToString(rdr["studentday"]);
                    TextBox4.Text = Convert.ToString(rdr["facultyday"]);
                    TextBox5.Text = Convert.ToString(rdr["firstweek"]);
                    TextBox6.Text = Convert.ToString(rdr["secondweek"]);
                    TextBox7.Text = Convert.ToString(rdr["thirdweek"]);

                }
                rdr.Close();
            }
            conn.Close();}

现在填写此表单后,我正在更改值并有一个"保存"按钮.

扼杀Button2_Click,当我尝试从文本框中访问编辑的值时,我没有获得新的值.文本框具有旧值.

为什么文本框没有编辑的值.

下面是我用来访问值的代码.

 using (SqlConnection conn = new SqlConnection("myconnectionstring"))
            {
                conn.Open();



                using (SqlCommand cmd = new SqlCommand("", conn))
                {
                    cmd.Parameters.Add("@rowno", SqlDbType.VarChar).Value = param; 

                    cmd.Parameters.AddWithValue("@tostudent", TextBox1.Text); 
                    cmd.Parameters.AddWithValue("@tofaculty", TextBox2.Text);
                    cmd.Parameters.AddWithValue("@studentday", TextBox3.Text);
                    cmd.Parameters.AddWithValue("@facultyday", TextBox4.Text);
                    cmd.Parameters.AddWithValue("@firstweek", TextBox5.Text);
                    cmd.Parameters.AddWithValue("@secondweek", TextBox6.Text);
                    cmd.Parameters.AddWithValue("@thirdweek", TextBox7.Text);


                    cmd.CommandText = "UPDATE addsetting SET tostudent=@tostudent,tofaculty=@tofaculty,studentday=@studentday,facultyday=@facultyday,firstweek=@firstweek,secondweek=@secondweek,thirdweek=@thirdweek WHERE rowno=@rowno";
                    cmd.ExecuteNonQuery();

                }

                conn.Close();

Answer 1

你在检查page_load中的IsPostBack属性吗？或者,无论是否有回发,您所概述的代码都会运行？

如果代码运行而不管回发那么你正在做的是在Button2_Click有机会访问它们之前覆盖TextBox值.这是因为在事件处理之前运行Load 的页面生命周期.

如果它不是回发(即用户没有单击提交按钮),您可能只希望page_load中的数据库检索运行,例如:

if (!Page.IsPostBack)
{
    using (SqlConnection conn = new SqlConnection("myconnectionString"))
    {
        conn.Open();
        using (SqlCommand cmmnd = new SqlCommand("", conn))
        {
            cmmnd.CommandText = "SELECT * FROM addsetting;";
            SqlDataReader rdr = cmmnd.ExecuteReader();

            while (rdr.Read())
            {
                count++;
                param = Convert.ToString(rdr["rowno"]);
                TextBox1.Text = Convert.ToString(rdr["tostudent"]);
                TextBox2.Text = Convert.ToString(rdr["tofaculty"]);
                TextBox3.Text = Convert.ToString(rdr["studentday"]);
                TextBox4.Text = Convert.ToString(rdr["facultyday"]);
                TextBox5.Text = Convert.ToString(rdr["firstweek"]);
                TextBox6.Text = Convert.ToString(rdr["secondweek"]);
                TextBox7.Text = Convert.ToString(rdr["thirdweek"]);
            }

            rdr.Close();
        }
    }
}