Hello Forum,

Currently I'm trying to create a contact form in my ASP.NET Core MVC Blog.

For realizing this, i followed ASP.Net Core Razor Pages: Contact Us Form.

Currently i have that code: My PageModel (cshtml.cs):

using System;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using MannsBlog.Models;
using MannsBlog.Services;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace MannsBlog.Views.Root
{    
    public class ContactModel : PageModel
    {        
        private IConfiguration _configuration;
        
        private GoogleCaptchaService _captcha;
        
        private IMailService _mailService;

        private ILogger<ContactModel> _logger;
      
        public string? Message { get; set; }
       
        public void IndexModel(IConfiguration configuration, GoogleCaptchaService captcha, IMailService mailService, ILogger<ContactModel> logger)
        {
            _configuration = configuration;
            _captcha = captcha;
            _mailService = mailService;
            _logger = logger;
        }
        
        public void OnGet()
        {
        }
        
        public async Task OnPostSubmit(ContactFormModel model)
        {
            try
            {
                if (ModelState.IsValid)
                {
                    var spamState = VerifyNoSpam(model);
                    if (!spamState.Success)
                    {
                        _logger.LogError("Spam detected. Break submitting proces..");
                        this.Message = "Spam detected. Sorry";
                    }

                    // Captcha
                    if (await _captcha.Verify(model.Recaptcha))
                    {
                        this.Message = "Recaptcha solved. That are good news.";
                        if (await _mailService.SendMailAsync("ContactTemplate.txt", model.Name, model.Email, model.Subject, model.Body, model.Attachment))
                        {
                            _logger.LogInformation("Captcha verified. Sent mail.");
                            this.Message = "Email sent.";
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                _logger.LogError("Failed to send email from contact page", ex);
            }
        }

        // Brute Force getting rid of my worst emails
        private SpamState VerifyNoSpam(ContactFormModel model)
        {
            var tests = new string[]
            {
        "improve your seo",
        "improved seo",
        "generate leads",
        "viagra",
        "your team",
        "PHP Developers",
        "working remotely",
        "google search results",
        "link building software",
            };

            if (tests.Any(t =>
            {
                return new Regex(t, RegexOptions.IgnoreCase).Match(model.Body).Success;
            }))
            {
                return new SpamState() { Reason = "Spam Email Detected. Sorry." };
            }

            return new SpamState() { Success = true };
        }
    }
}

My Page (cshtml):

@page
@addTagHelper*, Microsoft.AspNetCore.Mvc.TagHelpers
@using System.Net.Http
@using Microsoft.Extensions.Configuration;
@using Newtonsoft.Json.Linq
@using Microsoft.AspNetCore.Components.Forms
@using Microsoft.JSInterop
@using Microsoft.AspNetCore.Mvc.Localization
@using MannsBlog.Models
@inject IConfiguration _config
@inject IViewLocalizer _localizer
@model MannsBlog.Views.Root.ContactModel

@section styles {
    <link href="/css/contact.css" rel="stylesheet" />
    <style>
        .multiline {
            margin-top: 60px;
            width: 100%;
        }
    </style>
}

@section Scripts{
    <environment include="Development">
        <script type="text/javascript" src="~/lib/tinymce/tinymce.js"></script>
        <script type="text/javascript">
            tinymce.init({ selector: 'textarea', width: 300 });
        </script>
    </environment>
    <environment exclude="Development">
        <script type="text/javascript" src="~/lib/tinymce/tinymce.min.js"></script>
        <script type="text/javascript">
            tinymce.init({ selector: 'textarea', width: 300 });
        </script>
    </environment>
}

@{
    ViewBag.Title = _localizer["viewbag-title"];
    ViewBag.PageName = _localizer["viewbag-pagename"];
    ViewBag.PageBlurb = _localizer["viewbag-pageblurp"];
    ViewBag.PageImage = "/img/headers/code2.jpg";
}

<form method="post" enctype="multipart/form-data">
    <table border="0" cellpadding="0" cellspacing="0">
        <tr>
            <td style="width: 80px">Name:</td>
            <td><input type="text" name="Name" /></td>
        </tr>
        <tr>
            <td>Subject:</td>
            <td><input type="text" name="Subject" /></td>
        </tr>
        <tr>
            <td>Email:</td>
            <td><input type="text" name="Email" /></td>
        </tr>
        <tr>
            <td valign="top">Body:</td>
            <td><textarea cols="20" rows="10" name="Body"></textarea></td>
        </tr>
        <tr>
            <td>Attachment:</td>
            <td><input type="file" name="Attachment" /></td>
        </tr>
        <tr>
            <td></td>
            <td><input type="submit" value="Send" asp-page-handler="Submit" /></td>
        </tr>
    </table>
    <br />
    <span style="color:green">@Model.Message</span>
</form>

Currently the NullReferenceError happens by launching the Contact Page on the line with "@Model.Message".

I don’t know, but it feels, that i have forgotten anything.

It would be great, if anyone can spend one eye.

Greetings Sascha