带有生成的HTML代码的Web应用程序包含不显示消息的复选框。 （Asp.net，C＃）

Question

I found strange is that when I check some of the checkbox (generated HTML code), the sub function did not alert (or display message) which checkbox is being checked.

Am I missing something?

Inside the WebForm.aspx

 <script type="text/javascript">

 function sub()
 {

    for (i=0; i<arrChecks.length; i++)
    {
        var attribute = arrChecks[i].getAttribute("xid")
        if (attribute == elementName)
        {
            // if the current state is checked, unchecked and vice-versa
            if (arrChecks[i].checked)
            {
                arrChecks[i].checked = false;
            } else {
                arrChecks[i].checked = true;
                alert("Checked!");
            }

        } else {
            arrChecks[i].checked = false;
        }
    }

 }


 </script>

Inside the WebForm.cs

    protected void ButtonCheckDate_Click(object sender, EventArgs e)
    {
        SqlConnection conn = ConnectDB("Data Source=JACKSERVERA;Initial Catalog=tablea;User Id=tableuser;Password=tablepassword");


        if ((TextBox2.Text != null) && (TextBox2.Text != ""))
        {
            try
            {
                String res = "";

                SqlCommand command = conn.CreateCommand();
                SqlDataReader reader;
                command.CommandType = System.Data.CommandType.Text;
                command.CommandText = "SELECT * from overviewtable where [dated] = @PDATED";
                command.Parameters.AddWithValue("@PDATED", TextBox2.Text);
                command.Connection = conn;
                sqlstmt.Text = command.CommandText;

                conn.Open();
                reader = command.ExecuteReader();

                if (reader.HasRows)
                {
                    res = res + "<form name=\"input\" runat=\"server\"><table border=1>";
                    while (reader.Read())
                    {
                        res = res + "<tr>";


                        string thetime = (string)reader["time"];
                        string thevenue = (string)reader["venue"];
                        int numfreeseat = (int)reader["freeseat"];

                        int occupiedseat = 0;

                        SqlCommand bkcommand = conn.CreateCommand();
                        SqlDataReader bookinglist;
                        bkcommand.CommandType = System.Data.CommandType.Text;
                        bkcommand.CommandText = "SELECT count(*) from venuea where [dated] = @PDATED";
                        bkcommand.Parameters.AddWithValue("@PTIME", thetime);
                        bkcommand.Connection = conn;
                        sqlstmt.Text = bkcommand.CommandText;
                        bookinglist = bkcommand.ExecuteReader();

                        while (bookinglist.Read())
                        {
                            if (bookinglist.HasRows)
                            {
                                occupiedseat = (int)bookinglist.GetValue(0);
                            }
                        }


                        int leftnumofseat = numfreeseat - occupiedseat;

                        string color = "";
                        Boolean fullyoccupied = false;

                        if (leftnumofseat > 0)
                        {
                            if (leftnumofseat == numfreeseat)
                            {
                                // white
                                color = "#FFFFFF";
                            }
                            else
                            {
                                // light gray - partial occupied
                                color = "#B8B8B8";
                            }
                        }
                        else
                        {
                            // dark gray - fully occupied
                            color = "#505050";
                            fullyoccupied = true;
                        }


                        res = res + "<td bgcolor=\"" + color + "\">";
                        res = res + "Available: " + leftnumofseat + "/" + numfreeseat + "";
                        res = res + "</td>";

                        string checkboxval = TextBox2.Text + "_" + thetime + "_" + thevenue;

                        res = res + "<td>";
                        if (fullyoccupied == false)
                        {
                            res = res + "<input type=\"checkbox\" name=\"xid\" value=\"" + checkboxval + "\" runat=\"server\" />";
                        }
                        else
                        {
                            res = res + "FULL";
                        }
                        res = res + "</td>";

                        res = res + "</tr>";
                    }
                    res = res + "</table><input type=\"submit\" value=\"Submit\" OnClick=\"sub\" runat=\"server\"></form>";
                }
                LabelDateSelection.Text = res;

                conn.Close();



            }
            catch (Exception err)
            {
                errormsg.Text = err.Message;
            }
        }
        else
        {
            LabelDateSelection.Text = "Enter Date!";
        }



    }

Answer 1

Take out this part from you code & see if it works runat=\\"server\\"

i am not sure if you can create and ASP.net server control as you are trying too & you are sending output to the client while runat=\\"server\\" is rendered by the server . check you HTML code & see how it looks.

Create HTML control dynamically or create simple HTML control if that can work with your case.

look at the example how to pragmatically create controls

http://msdn.microsoft.com/en-us/library/kyt0fzt1%28v=vs.100%29.aspx

Answer 2

In addition to the points made by KnowledgeSeeker, you can't create asp controls in that style.

You can either get the values of the created checkboxes by using the FindControl method to locate the element and then get the value from it or in the C# add code similar to:

for (int i = 0; i < 5; i++)

{

CheckBox chk = new CheckBox();

chk.ID = Convert.ToString(i);

chk.Text = Convert.ToString(i);

form1.Controls.Add(chk);

}

In that instance you are looping from 0 to 5 and creating checkboxes and adding those controls to the form.