python之在 DefaultUserCreationForm 的模板中显示错误消息之django

我在 HTML 页面中显示错误消息时遇到问题。我将 Django 的默认 UserCreationForm 用于注册页面。它有两个密码字段 - 一个是原始密码，一个是确认密码。当用户输入不同的密码时，我得到 在/signup/而我希望在 HTML 页面中显示错误消息，指出密码不匹配。我已经浏览了文档并在我的代码中添加了一些相关行，我不知道我哪里出错了。

这是我的views.py:

def adduser(request): 
    if request.method == 'POST': 
        form = UserCreationForm(request.POST) 
        print(request.POST) 
 
        if(form.is_valid): 
            try: 
                user = employees.objects.get(emp_id=request.POST['username'] ) 
            except employees.DoesNotExist: 
                user = None 
 
            print(user) 
            if( user != None ): 
                if request.POST['username'] in  employees.objects.values_list('manager_id__emp_id',flat=True): 
                    g = Group.objects.get(name='Managers') 
                    newuser = form.save() 
                    newuser.groups.add(g) 
                else: 
                    g = Group.objects.get(name='Employees') 
                    newuser = form.save() 
                    newuser.groups.add(g) 
 
                return render(request,'login.html',{'form': form}) 
            else: 
                form = UserCreationForm() 
                return render(request,'signup.html', {'form': form, 'msg': 'Enter valid employee id'}) 
    else: 
        form = UserCreationForm() 
 
        return render(request,'signup.html', {'form': form}) 

这是我的 signup.html:

<body> 
    <div class="container"> 
        <div class="page-header"> 
            <h1>Sign-up Here</h1>       
        </div> 
        {% block body %} 
 
 
        <form method="post"> 
          {% csrf_token %} 
          <font color="orange" size="5px"><p> * Enter your Employee id, as username * </p></font> 
          {{ form.as_p }} 
          <font  color="red"> {{ msg }} </font><br> 
          <font  color="red"> {{ form.password1.errors }} </font><br> 
          <font  color="red"> {{ form.password2.errors }} </font><br> 
 
          <br> 
          <button class="btn btn-success" type="submit"> Go! </button> 
        </form> 
 
        {% endblock %}     
 
    </div> 
</body> 

请您参考如下方法:

问题出在这一行:

if(form.is_valid): 

这不是测试表单验证的正确方法， 而是使用:

if form.is_valid(): 

而且你不需要多次声明表单，它可以一次完成。 像这样:

def adduser(request): 
    form = UserCreationForm(request.POST or None) 
    if request.method == 'POST': 
        print(request.POST) 
        if form.is_valid(): 
            try: 
                user = employees.objects.get(emp_id=request.POST['username'] ) 
            except employees.DoesNotExist: 
                user = None 
 
            print(user) 
            if( user != None ): 
                if request.POST['username'] in  employees.objects.values_list('manager_id__emp_id',flat=True): 
                    g = Group.objects.get(name='Managers') 
                    newuser = form.save() 
                    newuser.groups.add(g) 
                else: 
                    g = Group.objects.get(name='Employees') 
                    newuser = form.save() 
                    newuser.groups.add(g) 
 
                return render(request,'login.html',{'form': form}) 
            else: 
                form = UserCreationForm() 
                return render(request,'signup.html', {'form': form, 'msg': 'Enter valid employee id'}) 
    return render(request,'signup.html', {'form': form}) 

并且可以有不同类型的错误，field 和 non_field_errors，所以使用这样的东西:

{% if form.errors %} 
    {% for field in form %} 
        {% for error in field.errors %} 
            <div class="alert alert-danger"> 
                <strong>{{ error|escape }}</strong> 
            </div> 
        {% endfor %} 
    {% endfor %} 
    {% for error in form.non_field_errors %} 
        <div class="alert alert-danger"> 
            <strong>{{ error|escape }}</strong> 
        </div> 
    {% endfor %} 
{% endif %}