模拟和模仿:

Create a formset which corresponds to the situation before clicking the "add" button. Load the page, view the source and take a note of all <input> fields. Modify the formset to correspond to the situation after clicking the "add" button (change the number of extra fields). Load the page, view the source and take a note of how the <input> fields changed. Create some JavaScript which modifies the DOM in a suitable way to move it from the before state to the after state. Attach that JavaScript to the "add" button.

虽然我知道表单集使用特殊的隐藏<input>字段，并且大约知道脚本必须做什么，但我不记得我头顶上的细节。我上面所描述的就是我在你的情况下会做的事情。

Paolo的答案的简化版本，使用empty_form作为模板。

<h3>My Services</h3>
{{ serviceFormset.management_form }}
<div id="form_set">
    {% for form in serviceFormset.forms %}
        <table class='no_error'>
            {{ form.as_table }}
        </table>
    {% endfor %}
</div>
<input type="button" value="Add More" id="add_more">
<div id="empty_form" style="display:none">
    <table class='no_error'>
        {{ serviceFormset.empty_form.as_table }}
    </table>
</div>
<script>
    $('#add_more').click(function() {
        var form_idx = $('#id_form-TOTAL_FORMS').val();
        $('#form_set').append($('#empty_form').html().replace(/__prefix__/g, form_idx));
        $('#id_form-TOTAL_FORMS').val(parseInt(form_idx) + 1);
    });
</script>

模拟和模仿:

Create a formset which corresponds to the situation before clicking the "add" button. Load the page, view the source and take a note of all <input> fields. Modify the formset to correspond to the situation after clicking the "add" button (change the number of extra fields). Load the page, view the source and take a note of how the <input> fields changed. Create some JavaScript which modifies the DOM in a suitable way to move it from the before state to the after state. Attach that JavaScript to the "add" button.

虽然我知道表单集使用特殊的隐藏<input>字段，并且大约知道脚本必须做什么，但我不记得我头顶上的细节。我上面所描述的就是我在你的情况下会做的事情。

我可以向每个正在寻找开箱即用解决方案的人推荐django-dynamic-formsets。

它取代了我从提出的解决方案中派生的所有代码，并提供了一些额外的功能，例如删除表单或对相关按钮进行风格化。

另一个cloneMore版本，允许对字段进行选择性消毒。当您需要防止多个字段被擦除时使用它。

$('table tr.add-row a').click(function() {
    toSanitize = new Array('id', 'product', 'price', 'type', 'valid_from', 'valid_until');
    cloneMore('div.formtable table tr.form-row:last', 'form', toSanitize);
});

function cloneMore(selector, type, sanitize) {
    var newElement = $(selector).clone(true);
    var total = $('#id_' + type + '-TOTAL_FORMS').val();
    newElement.find(':input').each(function() {
        var namePure = $(this).attr('name').replace(type + '-' + (total-1) + '-', '');
        var name = $(this).attr('name').replace('-' + (total-1) + '-','-' + total + '-');
        var id = 'id_' + name;
        $(this).attr({'name': name, 'id': id}).removeAttr('checked');

        if ($.inArray(namePure, sanitize) != -1) {
            $(this).val('');
        }

    });
    newElement.find('label').each(function() {
        var newFor = $(this).attr('for').replace('-' + (total-1) + '-','-' + total + '-');
        $(this).attr('for', newFor);
    });
    total++;
    $('#id_' + type + '-TOTAL_FORMS').val(total);
    $(selector).after(newElement);
}

是的，如果你有有限数量的条目，我也建议在html中渲染它们。(如果你不这样做，你将不得不使用另一个方法)。

你可以像这样隐藏它们:

{% for form in spokenLanguageFormset %}
    <fieldset class="languages-{{forloop.counter0 }} {% if spokenLanguageFormset.initial_forms|length < forloop.counter and forloop.counter != 1 %}hidden-form{% endif %}">

然后js真的很简单:

addItem: function(e){
    e.preventDefault();
    var maxForms = parseInt($(this).closest("fieldset").find("[name*='MAX_NUM_FORMS']").val(), 10);
    var initialForms = parseInt($(this).closest("fieldset").find("[name*='INITIAL_FORMS']").val(), 10);
    // check if we can add
    if (initialForms < maxForms) {
        $(this).closest("fieldset").find("fieldset:hidden").first().show();
        if ($(this).closest("fieldset").find("fieldset:visible").length == maxForms ){
            // here I'm just hiding my 'add' link
            $(this).closest(".control-group").hide();
        };
    };
}