问题描述：

登录的时候一直提示:用户名或者是密码错误，页面也不会跳转，但我输入的用户名和密码都没有错误

相关代码：

accounts/templates/login.html
​{% extends 'base.html' %}
{% from 'macro/form_errors.html' import form_field_errors %}
{% block title %}{{ super() }}-登录{% endblock %}
{% block header %}
    <link rel="stylesheet" href="./assets/style/login.css">
    <link rel="stylesheet" href="//at.alicdn.com/t/font_1658093_nokjvsp8hws.css">
{% endblock %}
{% block layout %}
    <div class="container">
        <div class="row">
            <div class="col-md-6 col-md-offset-3">
                {# 展示flash消息 #}
                {% include 'components/flash_messages.html' %}
                <!-- // 消息通知区域 -->
                <div class="login-header">
                    <h2 class="title text-center">在线问答系统登录</h2>
                    <div class="slogan text-center">有问题 上问答</div>
                </div>
                <!-- 表单登录 -->
                <!-- 表单登录 -->
                <form class="login-form box-wrap" method="POST"
                      action="{{ url_for('accounts.login') }}">
                    <input type="hidden" name="next" value="{{ next_url|d('') }}">
                    {{ form.csrf_token }}
                    <div class="form-group">
                        <label for="id-user-name">用户名</label>
                        {{ form.username }}
                    </div>
                    {{ form_field_errors(form.username.errors) }}
                    <div class="form-group">
                        <label for="id-password">密码</label>
                        {{ form.password }}
                    </div>
                    {{ form_field_errors(form.password.errors) }}
                    <div class="form-group">
                        <button type="submit" class="btn btn-info btn-block btn-lg">登录</button>
                    </div>
                    <p class="desc">未注册手机验证后自动登录<br/>
                        注册即代表同意《用户使用协议》《隐私保护指引》</p>
                    <p class="text-right">没有账号，<a href="{{ url_for('accounts.register') }}">点击注册</a></p>
                </form>
                <!-- //表单登录 -->
                <!-- 社交账号登录 -->
                <div class="login-social box-wrap">
                    <span>社交账号登录</span>
                    <div class="right">
                        <span><i class="iconfont icon-wechat"></i>微信</span>
                        <span><i class="iconfont icon-qq"></i>QQ</span>
                        <span><i class="iconfont icon-weibo"></i>微博</span>
                    </div>
                </div>
                <!-- //社交账号登录 -->
                <!-- 页脚 -->
                <div class="login-footer">
                    <a href="">关于我们</a>
                    <a href="">联系我们</a>
                    <a href="">注册机构</a>
                    <a href="">专栏</a>
                    <br>
                    <a href="">京ICP 备1000000012号</a>
                </div>
            </div>
        </div>
    </div>
{% endblock %}

accounts/forms.py
import hashlib

from flask import request
from flask_login import login_user
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, ValidationError
from wtforms.validators import DataRequired, Length, EqualTo

from models import User, db, UserProfile, UserLoginHistory
from utils import constants
from utils.validators import phone_required


class RegisterForm(FlaskForm):
    """ 用户注册 """
    username = StringField(label='用户名', render_kw={
        'class': 'form-control input-lg',
        'placeholder': '请输入用户名'
    }, validators=[DataRequired('请输入用户名'), phone_required])
    nickname = StringField(label='用户昵称', render_kw={
        'class': 'form-control input-lg',
        'placeholder': '请输入用户昵称'
    }, validators=[DataRequired('请输入用户昵称'),
                   Length(min=2, max=20, message='昵称长度在2-20之间')])
    password = PasswordField(label='密码', render_kw={
        'class': 'form-control input-lg',
        'placeholder': '请输入密码'
    }, validators=[DataRequired('请输入密码')])
    confirm_password = PasswordField(label='确认密码', render_kw={
        'class': 'form-control input-lg',
        'placeholder': '请输入确认密码'
    }, validators=[DataRequired('请输入确认密码'),
                   EqualTo('password', message='两次密码输入不一致')])

    def validate_username(self, field):
        """ 检测用户名是否已经存在 """
        user = User.query.filter_by(username=field.data).first()
        if user:
            raise ValidationError('该用户名已经存在')
        return field

    def register(self):
        """ 自定义的用户注册函数 """
        # 1. 获取表单信息
        username = self.username.data
        password = self.password.data
        nickname = self.nickname.data
        # 2. 添加到db.session
        try:
            # 将密码加密存储
            password = hashlib.sha256(password.encode()).hexdigest()
            user_obj = User(username=username, password=password, nickname=nickname)
            db.session.add(user_obj)
            profile = UserProfile(username=username, user=user_obj)
            db.session.add(profile)
            db.session.commit()
            return user_obj
        except Exception as e:
            print(e)
        return None


class LoginForm(FlaskForm):
    """ 用户登录 """
    username = StringField(label='用户名', render_kw={
        'class': 'form-control input-lg',
        'placeholder': '请输入用户名'
    }, validators=[DataRequired('请输入用户名'), phone_required])
    password = PasswordField(label='密码', render_kw={
        'class': 'form-control input-lg',
        'placeholder': '请输入密码'
    }, validators=[DataRequired('请输入密码')])

    def validate(self):
        result = super().validate()
        username = self.username.data
        password = self.password.data
        if result:
            # TODO 验证加密后的密码是否正确
            user = User.query.filter_by(username=username, password=password).first()
            if user is None:
                result = False
                self.username.errors = ['用户名或者是密码错误']
            elif user.status == constants.UserStatus.USER_IN_ACTIVE.value:
                result = False
                self.username.errors = ['用户已被禁用']
        return result

    def do_login(self):
        """ 执行登录逻辑代码 """
        username = self.username.data
        password = self.password.data
        try:
            # 1. 查找对应的用户
            # TODO 验证加密后的密码是否正确
            user = User.query.filter_by(username=username, password=password).first()
            # 2. 登录用户
            # session['user_id'] = user.id
            login_user(user)
            # 3. 记录日志
            ip = request.remote_addr
            ua = request.headers.get('user-agent', None)
            obj = UserLoginHistory(username=username, ip=ip, ua=ua, user=user)
            db.session.add(obj)
            db.session.commit()
            return user
        except Exception as e:
            print(e)
        return None

相关截图：

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