Button.Touch firing multiple times when only touched once

Question

I'm working on an app through xamarin and I'm using a Button to check registration fields.

Button sendToRegisterButton = (Button)FindViewById(Resource.Id.registerbtn);
sendToRegisterButton.Touch += delegate { CheckFields(); };

So when the button is touched, I check for a boolean touchedto see if the button has already been pressed.

I set touched to true if the if(!touched) passes. I let the code run and at the end of the if statement I set touched to false again. Now, when I test this and press the register button on my phone, the checkfields function is still called multiple times.

Relevant Code:

    private void CheckFields()
    {
        if (!touched)
        {
            touched = true;
            //Rest of code here... checking the username and password fields etc
            touched = false;
        }
    }

EDIT: I tried disabling the button and reenabling it afterwards, didn't work unfortunately

    private void CheckFields()
    {
        sendToRegisterButton.Enabled = false;
        //Rest of code here... checking the username and password fields etc
        sendToRegisterButton.Enabled = true;

    }

EDIT2: Since people were asking, this is the whole class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using ArcheologieApplication.Code;
using System.Text.RegularExpressions;
using ArcheologieApplication.Code.Queries;

namespace ArcheologieApplication
{
    [Activity(Label = "ArcheologieApplication", MainLauncher = true, Theme = "@android:style/Theme.Black.NoTitleBar.Fullscreen")]
    class RegisterActivity : Activity
    {
        private Button sendToRegisterButton;

        PlayerInfoQuery playerQuery = new PlayerInfoQuery();

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            SetContentView(Resource.Layout.RegisterLayout);
            SetupButtons();
        }

        private void SetupButtons()
        {
            Button loginButton = (Button)FindViewById(Resource.Id.signinbtn);
            loginButton.Touch += delegate { StartActivity(typeof(LoginActivity)); };

            sendToRegisterButton = (Button)FindViewById(Resource.Id.registerbtn);
            sendToRegisterButton.Touch += delegate { CheckFields(); };
        }
        private void CheckFields()
        {
            sendToRegisterButton.Enabled = false;
            RegexUtilities checkMail = new RegexUtilities();

            var username = FindViewById<EditText>(Resource.Id.regnametxt);
            var userEmail = FindViewById<EditText>(Resource.Id.regemailtxt);
            var userPassword = FindViewById<EditText>(Resource.Id.regpasstxt);
            var userPasswordConfirm = FindViewById<EditText>(Resource.Id.regconfirmtxt);
            PlayerInfo player = new PlayerInfo();

            bool nameBool = false;
            bool emailBool = false;
            bool passBool = false;

            if (string.IsNullOrEmpty(username.Text))
            {
                Toast.MakeText(this, "Invalid Username", ToastLength.Short).Show();

            }
            else
            {
                player.PlayerName = username.Text;
                nameBool = true;
            }
            if (string.IsNullOrEmpty(userEmail.Text))
            {
                //TODO: Verify Email adress for valid email.
                Toast.MakeText(this, "Invalid Email Adress", ToastLength.Short).Show();
            }
            else
            {
                if (checkMail.IsValidEmail(userEmail.Text))
                {
                    player.PlayerEmail = userEmail.Text;
                    emailBool = true;
                }
                else
                {
                    Toast.MakeText(this, "Invalid Email Adress", ToastLength.Short).Show();
                }

            }
            if (string.IsNullOrEmpty(userPassword.Text) || string.IsNullOrEmpty(userPasswordConfirm.Text))
            {
                Toast.MakeText(this, "Invalid Password Invalid", ToastLength.Short).Show();
            }
            else
            {
                if (userPassword.Text != userPasswordConfirm.Text)
                {
                    Toast.MakeText(this, "Passwords not the same", ToastLength.Short).Show();
                }
                else
                {
                    PasswordHasher hasher = new PasswordHasher();

                    byte[] saltBytes = hasher.GenerateRandomSalt(PasswordHasher.saltByteSize);
                    string saltString = Convert.ToBase64String(saltBytes);

                    string passwordHash = hasher.PBKDF2_SHA256_GetHash(userPassword.Text, saltString,
                        PasswordHasher.iterations, PasswordHasher.hashByteSize);

                    Console.WriteLine("SALT: " + saltString.Length);
                    Console.WriteLine("HASH: " + passwordHash.Length);

                    string hashedPwd = saltString + passwordHash;
                    player.PlayerPassword = hashedPwd;
                    passBool = true;
                }
            }
            //If everything is correct insert into database
            if (nameBool && emailBool && passBool)
            {
                player.PlayerPoints = 0; //Standard is 0
                playerQuery.Insert(player);
                Toast.MakeText(this, "Thank you for registering, please login", ToastLength.Long).Show();

                StartActivity(typeof(LoginActivity));
            }

            sendToRegisterButton.Enabled = true;
        }
    }
}

Answer 1

The Touch event handler is called for touch down, up and motion events.

It looks like you are trying to handle a click on the buttons; consider using the Clicked event callback instead (which will only fire when the user touches down and then releases your button):

private void SetupButtons()
    {
        Button loginButton = (Button)FindViewById(Resource.Id.signinbtn);
        loginButton.Clicked += delegate { StartActivity(typeof(LoginActivity)); };

        sendToRegisterButton = (Button)FindViewById(Resource.Id.registerbtn);
        sendToRegisterButton.Clicked += delegate { CheckFields(); };
    }