My problem is that My asp.net Button's onclick behaviour does not work because on code behind btnSendMail_Click show's 0 reference. I added my code and code behind and my error's message. Normally I have used this method several times but this time I couldn't do it.

Some of my html code

<div class="col-lg-8" runat="server">
                <div class="contact-form section-top-gap-100" data-aos="fade-up"  data-aos-delay="200">
                    <asp:Label Text="<%$Resources:Lang, ContactUs %>" runat="server" Font-Size="Large" Font-Bold="true"></asp:Label>
                    <div id="contact-form">
                        <div class="row">
                            <div class="col-lg-6">
                                <div class="default-form-box mb-20">
                                   <asp:Label Text="<%$Resources:Lang, Name %>" runat="server" Font-Bold="true"></asp:Label>
                                    <input name="name" type="text" id="contactName" runat="server" placeholder="<%$Resources:Lang, NamePlaceHolder %>" >
                                    
                                </div>
                            </div>
                            <div class="col-lg-6">
                                <div class="default-form-box mb-20">
                                   <asp:Label Text="<%$Resources:Lang, mail %>" runat="server" Font-Bold="true"></asp:Label>
                                    <input name="email" type="email" id="contactEmail" runat="server" placeholder="<%$Resources:Lang, mailPlaceHolder %>" >
                                </div>
                            </div>
                            <div class="col-lg-12">
                                <div class="default-form-box mb-20">
                                   <asp:Label Text="<%$Resources:Lang, subject %>" runat="server" Font-Bold="true"></asp:Label>
                                    <input name="subject" type="text" id="contactSubject" runat="server" placeholder="<%$Resources:Lang, SubjectPlaceHolder %>">
                                </div>
                            </div>
                            <div class="col-lg-12">
                                <div class="default-form-box mb-20">
                                   <asp:Label Text="<%$Resources:Lang, message %>" runat="server" Font-Bold="true"></asp:Label>
                                    <textarea name="message" id="contactMessage" cols="30" rows="10" runat="server" placeholder="<%$Resources:Lang, MessagePlaceHolder %>" ></textarea>
                                </div>
                            </div>
                            <div class="col-lg-12">
                                <asp:Button runat="server" CssClass="contact-submit-btn" Text="<%$Resources:Lang, sendMessage %>" ID="btnSendMail" OnClick="btnSendMail_Click" UseSubmitBehavior="true"/>
                            </div>
                            <p class="form-messege"></p>
                            
                        </div>
                    </div>
                </div>
            </div>

My code behind

    using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Mail;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace AsjSpray.Web.Pages
{
    public partial class Iletisim : BasePage
    {
        #region Properties
        public static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType); 
        #endregion
        protected void Page_Load(object sender, EventArgs e)
        {
            Page.Title = "AsjSpray "   Resources.Lang.ContactUs;
            log.Info("İletişim Sayfasına girildi");
        }

        private static string GetIp()
        {
            string VisitorsIPAddress = string.Empty;
            try
            {
                if (HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
                {
                    VisitorsIPAddress = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
                }
                else if (HttpContext.Current.Request.UserHostAddress.Length != 0)
                {
                    VisitorsIPAddress = HttpContext.Current.Request.UserHostAddress;
                }
            }
            catch (Exception ex)
            {
                log.Error("Hata [Iletisim.GetIp()]"   ex.Message);
            }
            return VisitorsIPAddress;
        }

        bool IsValidEmail(string email)
        {
            try
            {
                var addr = new System.Net.Mail.MailAddress(email);
                return addr.Address == email;
            }
            catch
            {
                return false;
            }
        }

        protected void btnSendMail_Click(object sender, EventArgs e)
        {
            var senderMessage = contactMessage.Value;
            var senderName = contactName.Value;
            var senderMail = contactEmail.Value;
            var subject = contactSubject.Value;
            var ipAddress = GetIp();


            SmtpClient smtpClient = new SmtpClient();

            NetworkCredential basicCredential = new NetworkCredential("[email protected]", "pass");

            MailMessage message = new MailMessage();

            MailAddress fromAddress = new MailAddress("[email protected]");

            smtpClient.Host = "mail.asjspray.com";

            smtpClient.UseDefaultCredentials = false;

            smtpClient.Credentials = basicCredential;

            smtpClient.Port = 587;

            smtpClient.EnableSsl = true;

            message.From = fromAddress;

            message.Subject = subject;

            //Set IsBodyHtml to true means you can send HTML email.

            message.IsBodyHtml = true;

            message.Body = "Gönderici adı: "   senderName   "<br/> Gönderici maili: "   senderMail   "<br/> Gönderici mesajı: "   senderMessage   "<br/> Gönderici ip adresi: "   ipAddress; ;

            message.To.Add("[email protected]");

            message.Bcc.Add("");


            try

            {
                ServicePointManager.ServerCertificateValidationCallback = delegate (object s,
                    X509Certificate certificate,
                    X509Chain chain,
                    SslPolicyErrors sslPolicyErrors)
                {
                    return true;
                };
                if (senderMessage != null && senderName != null &&
                    senderMail != null)
                {
                    smtpClient.Send(message);
                    ScriptManager.RegisterStartupScript(this, GetType(), "CallFunction", "successful();", true);
                    log.Info("Mail gönderme başarılı mail adresi: "   senderMail);
                }
                else if (IsValidEmail(senderMail) == false)
                {
                    ScriptManager.RegisterStartupScript(this, GetType(), "CallFunction", "emptyMail();", true);
                    log.Warn("Mail gönderilmedi mail geçersiz "   senderMail);
                }
                else
                {
                    ScriptManager.RegisterStartupScript(this, GetType(), "CallFunction", "hata();", true);
                    log.Error("Mail gönderilmedi");
                }


            }

            catch (Exception ex)

            {
                log.Error("Hata, Mail gönderilemedi "   ex.Message);
                Response.Write(ex.Message);
                Page.Response.Write("<script>console.log('"   ex.Message   "');</script>");

            }
        }
    }
    }

My Error Image

So, click on create new event. It LOOKS like nothing occured, but if you now flip to code behind, then you see the code stub.

Give above a try - you should not even need that UseSubmit behavour.

CodePudding user response：

I solved the problem. It is because I have "required" property in MasterPage search bar. It prevented click to button.