Issues with onclick/onserverclick with buttons, HtmlButtons, and LinkButtons

Question

I'm having an issue with the functions to be called not firing off.

I have moved from hardcoding the buttons on HTML, to using the add controls method in the cs; and I have shifted from using Button and HtmlButton to using LinkButton. However none of these seem to work. In Onserverclick and onclick not work Anup Sharma recommends using the LinkButton, and Keyvan Sadralodabai indicates that if the runat="server" is displayed in the insect element, then he control was set up wrong.

So here's a stripped down simplified version of what I'm working with:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.Drawing;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Web.UI.HtmlControls;
    using System.Web.Services;

    using System.Data;
    using MySql.Data;
    using MySql.Data.MySqlClient;

    public partial class backCodeExper : System.Web.UI.Page
    {

        protected void saveRecord(string recordID, string buttonId, string dropdownId)
        {

            PlaceHolder db = Page.FindControl("TestingCS") as PlaceHolder;
            HtmlTable tbl = db.FindControl("TestTable") as HtmlTable;
            HtmlTableRow tr = tbl.FindControl("TheRow") as HtmlTableRow;
            HtmlTableCell tc = tr.FindControl("TheCell2") as HtmlTableCell;
            DropDownList ddl = tc.FindControl(dropdownId) as DropDownList;


            var status = ddl.SelectedValue.ToString();

            HttpContext context = HttpContext.Current;
            MySqlConnection conn = new MySqlConnection();
            conn.ConnectionString = "Server=localhost; Database********; User=********; Password=********; Port=3306"; 
            conn.Open();
            MySqlCommand cmd = new MySqlCommand();
            cmd.Connection = conn;
            cmd.CommandType = CommandType.StoredProcedure;

            cmd.CommandText = "updatetesttable";
            cmd.Parameters.AddWithValue("@param", status);
            cmd.ExecuteNonQuery();
        }

        protected void Page_Load(object sender, EventArgs e)
        {
            HtmlTable myTable = new HtmlTable();
            myTable.ID = "TestTable";
            myTable.BorderColor = "teal";
            myTable.BgColor = "black";
            TestingCS.Controls.Add(myTable);

            HtmlTableRow newRow;
            HtmlTableCell cell;
            DropDownList DropList;
            LinkButton saveButton;

            newRow = new HtmlTableRow();
            newRow.ID = "TheRow";
            cell = new HtmlTableCell();
            cell.ID = "TheCell1";
            DropList = new DropDownList();
            DropList.ID = "StatusDD";
            DropList.Items.Add(new ListItem("", "0"));
            DropList.Items.Add(new ListItem("A", "1"));
            DropList.Items.Add(new ListItem("B", "2"));
            DropList.Items.Add(new ListItem("C", "3"));
            cell.Controls.Add(DropList);

            newRow.Cells.Add(cell);

            cell = new HtmlTableCell();
            cell.ID = "TheCell2";
            cell.BgColor = "black";
            saveButton = new LinkButton();
            saveButton.ID = "saveButton";

            saveButton.CommandName = "saveRecord";
            saveButton.CommandArgument = "'1A',this.id,'StatusDD'";
            saveButton.BackColor=Color.Green;
            saveButton.ForeColor=Color.Cyan;
            saveButton.BorderColor=Color.Maroon;
            saveButton.Text = "Save";
            saveButton.Visible = true;
            cell.Controls.Add(saveButton);
            newRow.Cells.Add(cell);
            myTable.Rows.Add(newRow);
        }
    }

It loads the screen just fine with the simple dropdown and with the (unstylish) button (frankly the HtmlButton looks much nicer, but I'm aiming for functionality first).

When I select an item from the dropdown and then click save, the screen appears to refresh, keeping the value of the dropdown the same as that which was selected. However, when I check the database, the procedure hasn't fired. Additionally I cannot get this code segment Response.Write("<script>alert('Hello');</script>"); to execute when placed in the method/function saveRecord.

Furthermore, when I run the debugging mode and put break points in saveRecord, none of them are hit.

After inspecting element, this is what I get: InspectElementResults

Any suggestions? What am I missing? If I don't use LinkButton (or Button/HtmlButton with onServerClick) then I get errors saying the function isn't defined - which makes since as the function/method is define on the aspx.cs not the aspx within JS script tags.

Answer 1

I've got it figured out. At least, it is functional.

I was trying to set the function to pass the values I want in the format I wanted, but apparently the when you set up a LinkButton, it prefers the object and Event Args as parameters, and the object is the ListButton itself, so if that ListButton object holds the values you need in its attributes, then when the function is called you parse out the attributes you need. There's likely a better way than to assign the two values I need to CommandName and CommandArgument, but this works. (I had thought of using .Attributes.Add("ROW_ID","1a") and .Attributes.Add("DD_ID","StatusDD") ... but couldn't initially figure out how to retrieve those values from the sender object...to be investigated later, in the meantime, rolling forward with a functional solution.

    ...
        protected void saveRecord(object sender, EventArgs e)
        {
            LinkButton lb = (LinkButton)sender;
            string ROW_ID = (string)lb.CommandName;
            string DD_ID = (string)lb.CommandArgument;
            Response.Write("<script>alert('Hello');</script>");
            ...
        }

        protected void Page_Load(object sender, EventArgs e)
        {
            ...

            saveButton.CommandName = "1a";
            saveButton.CommandArgument = "StatusDD";
            saveButton.Click += new EventHandler(saveRecord);
            ...
        }
    }