html - 在 Django 中提交后保留选择选项值

Question

我没有使用 Ajax 或 Django 表单。我在表单标签内有纯 HTML 选择标签，并在我的 View 中发送选定的选项值。我想在提交后保留选择选项值。目前，无论我的选择如何，它都会达到默认值 1。帮助将不胜感激。

这是我的模板代码:

            <form method = "post" action = "{% url 'index' %}">
                {% csrf_token %}
                <label class="mainlbl">Vega</label>
                <select name = "drop1" >
                    <option value="1">1</option>
                    <option value="2">2</option>
                    <option value="3">3</option>
                    <option value="4">4</option>
                    <option value="5">5</option>
                    <option value="6">6</option>
                    <option value="7">7</option>
                    <option value="8">8</option>
                    <option value="9">9</option>
                    <option value="10">10</option>
                    <option value="11">11</option>
                    <option value="12">12</option>
                </select>
                <input class="btn btn-ocean btn-side-bar" type = "submit" value="Submit">
            </form>

我的观点是:

def index(request):
    if request.method == "POST":
        vega = request.POST['drop1']
        vega = int(vega)
        gvo = GVOptimize('NSE', 'Nifty')
        data = gvo.get_optimal_strategies(vega)
        str1 = None

        for i in range(0, len(data)):
            if i == 0:
                str1 = data[i]

            elif i == 1:
                str2 = data[i]

            elif i == 2:
                str3 = data[i]

            elif i == 3:
                str4 = data[i]

            else:
                break
        context_dict = {'str1': str1, 'str2': str2, 'str3': str3, 'str4': str4 'vega': vega}
        return render(request, 'demo/dashboard.html', context_dict)
    else:
        context_dict = {}
        return render(request, 'demo/dashboard.html', context_dict)

Answer 1

如果您真的坚持使用一种 hacky 方式来维护所选选项，您可以更改表单以检查每个选项以查看它是否等于您在上下文中传回的数字

<form method = "post" action = "{% url 'index' %}">
    {% csrf_token %}
    <label class="mainlbl">Vega</label>
    <select name = "drop1" >
        {% for idx in "useaformpls!" %}
            <option value="{{ forloop.counter }}" {% if context_val == forloop.counter %}selected {% endif %}>
                 {{ forloop.counter }}
             </option>
        {% endfor %}
    </select>
    <input class="btn btn-ocean btn-side-bar" type = "submit" value="Submit">
</form>

其中 context_val 等于您在 View 的上下文数据中传回的索引。