public async void BtnLogin_Click(object sender, EventArgs e) { email = login_accounts.Text; password = login_password.Text; bool isNetWorking = Utils.isNetworkAvailable(this); if (isNetWorking == true) { if (string.IsNullOrEmpty(email) || string.IsNullOrEmpty(password)) { DialogFactory.ToastDialog(this, "Login", "Username and password cannot be empty!", 0); } else { //check email Match match = Regex.Match(email, "^(\\w)+(\\.\\w+)*@(\\w)+((\\.\\w{2,3}){1,3})$"); //if (match.Success) { ll_loginpage.Alpha = 0.5f; try { result = await MusicoConnUtil.AuthenticateUser(email, password); } catch (Exception) { ll_loginpage.Alpha = 1.0f; AlertDialog.Builder ab = new AlertDialog.Builder(this); ab.SetTitle("Server busy"); ab.SetMessage("Server is busy,please try again later!"); ab.SetPositiveButton("confirm", delegate(object sndr, DialogClickEventArgs ee) { }); ab.Create().Show(); } if (result > 0) { //login successfull Toast.MakeText(this, "Login successfull!", ToastLength.Short).Show(); Intent intent = new Intent(this, typeof(HomeActivity)); intent.PutExtra("email", email); intent.PutExtra("id", result + ""); StartActivity(intent); Finish(); } else { ll_loginpage.Alpha = 1.0f; //failed DialogFactory.ToastDialog(this, "Login", "Username or password is not correct!", 0); //to do:specific error msg } //} else { // ll_loginpage.Alpha = 1.0f; // DialogFactory.ToastDialog (this, "Login", "Email format is incorrent!", 0); //} } } else { DialogFactory.ToastDialog(this, "Connect Error", "There is no internet,please connect the internet!", 0); } }