# 添加书籍:
def add(reqeust):
    if GET请求:
        form=BookModelForm()
        return render(reqeust,{"form":form})
    else POST请求:
        form=BookModelForm(request.POST)
        if form.is_valid():
            form.save() # Book.objects.create(clean_data)
            return redirect("/")
        else:
            return render(reqeust,{"form":form})
                               
    '''
    HTML渲染页面代码
      <form action="" method="post" novalidate>
            {% csrf_token %}
              {% for field in form %}
                    <div class="form-group">
                         <label for="title">{{ field.label }}</label>
                         {{ field }}
                         <span>{{ field.errors.0 }}</span>
                    </div>
             {% endfor %}
            <input type="submit" value="提交" class="btn btn-default pull-right">
      </form>
    '''