如何将runat = server属性添加到html按钮

Question

I have multiple html buttons that generated from server side with a method on a csharp class.
the result is:

<button ID='btn1' runat='server' onserverclick='btn_Click'>Apply</button>
<button ID='btn2' runat='server' onserverclick='btn_Click'>Apply</button>
<button ID='btn3' runat='server' onserverclick='btn_Click'>Apply</button>
...
<button ID='btnN' runat='server' onserverclick='btn_Click'>Apply</button>

I also add btn_Click event to behind code:

protected void btn_Click (object sender, EventArgs e)
{
    string id = (sender as Control).ClientID;
    msg = id;
}

as you can see I want to get buttonId but when I click on any of buttons, btn_Click won't call and I can't get buttonId.
I am using asp.net website with c#4.0.

The problem is I need generate buttons using server side and runat attribute doesn't work with my method . how can I fix this problem?
this is my method body for generated buttons

for (int i = 0; i < dt.Rows.Count; i++)
        {
            DateTime dtTemp = DateTime.Parse(dt.Rows[i]["messageDate"].ToString());
            if (dt.Rows[i]["isRead"].ToString() == "True")
                readed = "MessageReaded";
            else
                readed = "MessageNew";
            post += "<div class='modal fade' id='myModal" + dt.Rows[i]["messageId"].ToString() + "' tabindex='-1' role='dialog' aria-labelledby='myModalLabel'>"
                + "<div class='modal-dialog' role='document'>"
                + "<div class='modal-content'>"
                + "<div class='modal-header'><button type='button' class='close' data-dismiss='modal' aria-label='Close'><span aria-hidden='true'>&times;</span></button><h4 class='modal-title' id='myModalLabel'><span style='font-weight:bold'>subject</span> : " + dt.Rows[i]["subject"].ToString() + "</h4></div>"
                + "<div class='modal-header'><p><span style='font-weight:bold'>date</span> : " + dtTemp.ToString("yyyy/MM/dd") + "</p>"
                + "<p><span style='font-weight:bold'>Time</span> : " + dt.Rows[i]["messageTime"].ToString() + "</p>"
                + "<p><span style='font-weight:bold'>email</span> : " + dt.Rows[i]["email"].ToString() + "</p></div>"
                + "<div class='modal-body'>" + dt.Rows[i]["message"].ToString() + "</div>"
                + "<div class='modal-footer'><button type='button' class='btn btn-default' data-dismiss='modal'>close</button>"
                + "<button ID='btn" + dt.Rows[i]["messageId"].ToString() + "'  class='btn btn-danger' onclick='DeleteMessage_Click'>Delete</button></div>"
                + "</div></div></div>";
            string narrow = Special.TimeToNarrow(dt.Rows[i]["messageDate"].ToString(), dt.Rows[i]["messageTime"].ToString());
            post += "<a data-toggle='modal' data-target='#myModal" + dt.Rows[i]["messageId"].ToString() + "' href='#' class='list-group-item " + readed + "'><span class='badge'>" + narrow + "</span><i class='fa fa-fw fa-comment'></i> <span>"
                     + dt.Rows[i]["name"].ToString() + "</span> : <span>" + dt.Rows[i]["subject"].ToString() + "</span></a>";
        }

So the problem is on
<button ID='btn" + dt.Rows[i]["messageId"].ToString() + "' runat='server' class='btn btn-danger' onserverclick='DeleteMessage_Click'>Delete</button>

EDIT MY POST : As you can see I can't use asp:button because using bootstrap modal. If you think that I can still use asp:button please write your code and show me how .thanks

Answer 1

There's no onserverclick in asp. You should add the asp:Button tag instead of just Button and instead of onserverclick just OnClick

Something like:

<asp:Button ID='btn1' runat='server' Text="Apply" OnClick='btn_Click'/>

EDIT The button generation method should look like this:

for (int i = 0; i < dt.Rows.Count; i++){
<div class='modal fade' id='myModal" + dt.Rows[i]["Id"].ToString() + "' tabindex='-1' role='dialog' aria-labelledby='myModalLabel'>
     <div class='modal-dialog' role='document'>
          <div class='modal-content'>
              <div class='modal-header'><button type='button' class='close' data-dismiss='modal' aria-label='Close'><span aria-hidden='true'>&times;</span></button><h4 class='modal-title' id='myModalLabel'><span style='font-weight:bold'>subject</span> :subject</h4></div>
              <div class='modal-header'><p><span style='font-weight:bold'>Date</span> : yyyy/MM/dd</p>
                    <p><span style='font-weight:bold'>Time</span>messageTime</p>
                    <p><span style='font-weight:bold'>Email</span>email</p>
              </div>
              <div class='modal-body'>message</div>
              <div class='modal-footer'>
                   <button type='button' class='btn btn-default' data-dismiss='modal'>close</button>
                   <asp:Button ID='btn" + dt.Rows[i]["messageId"].ToString() + "' runat='server'  class='btn btn-danger' OnClick='DeleteMessage_Click'>Delete</button> 
              </div>
          </div>
     </div>

You can see that on this line: <button ID='btn" + dt.Rows[i]["messageId"].ToString() + "' runat='server' class='btn btn-danger' onserverclick='DeleteMessage_Click'>Delete</button> i have changed the button with asp:Button and the onserverclick with OnClick .

Answer 2

As other's have said, the problem is ASP.NET won't recognise runat="server" when you generate your controls as a string of HTML.

Your code should probably be done in a much different way, but if you wanted a change to what you have already done that will work you could do this a little differently.

Instead of runat="server" on your buttons, make them submit buttons and assign them a name and value, for example...

Instead of this:

<button ID='btn1' runat='server' onserverclick='btn_Click'>Apply</button>
<button ID='btn2' runat='server' onserverclick='btn_Click'>Apply</button>
<button ID='btn3' runat='server' onserverclick='btn_Click'>Apply</button>

Do this (note they all have the same name):

<button name="btn" type="submit" value="1">Apply</button>
<button name="btn" type="submit" value="2">Apply</button>
<button name="btn" type="submit" value="3">Apply</button>

Then in your Page_Load event you can detect if one of these buttons was clicked with the following:

if (Page.IsPostBack)
{
    if (Request.Form["btn"] != null)
    {
         //A btn was clicked, get it's value
         int btn = int.Parse(Request.Form["btn"]);

         //Do something with this btn number
    }
}

Here's a little sample that has three buttons and displays the number of the button that was clicked:

Test.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Test.aspx.cs" Inherits="Test" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <button name="btn" type="submit" value="1">Apply</button>
        <button name="btn" type="submit" value="2">Apply</button>
        <button name="btn" type="submit" value="3">Apply</button>
    </form>
</body>
</html>

test.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Test : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Page.IsPostBack)
        {
            if (Request.Form["btn"] != null)
            {
                int btn = int.Parse(Request.Form["btn"]);

                Response.Write(btn);
            }
        }
    }
}

Answer 3

The previous comments are correct, there is no onserverclick in asp.net server control. onserverclick is available for html controls only. Below code piece does the job;

protected void btn1_ServerClick(object sender, EventArgs e)
{
    HtmlButton btn = (HtmlButton)sender;

    btn.InnerText = btn.ID;
}

Cast the sender to HtmlButton to access the ID. You have to use the namespace 'System.Web.UI.HtmlControls'.

EDIT:

If the buttons are being dynamically generated then better to use server button control;

 <asp:Button ID="btnAddUser" runat="server" Text="Add"  OnClick="btnAddUser_Click" />