之前没有任何问题，到做edit_entry的时候报错了
NoReverseMatch at /topics/2/
Reverse for 'edit_entry' with arguments '('',)' not found. 1 pattern(s) tried: ['edit_entry/(?P\d+)/']
urls页面：
from django.urls import path, re_path
from . import views
app_name = 'learning_logs'
urlpatterns = [
#主页
path('', views.index, name='index'),
#显示所有主题
path('topics/', views.topics, name='topics'),
#特定主题的详细页面
re_path('topics/(?P<topic_id>\d+)/', views.topic, name='topic'),
#用于添加新主题的网页
path('new_topic/', views.new_topic, name='new_topic'),
#用于添加新条目的页面
re_path('new_entry/(?P<topic_id>\d+)/', views.new_entry, name='new_entry'),
#用于编辑条目的页面
re_path('edit_entry/(?P<entry_id>\d+)/', views.edit_entry, name='edit_entry'),
]
views页面：
from django.shortcuts import render
from django.http import HttpResponseRedirect
from django.urls import reverse
from .models import Topic, Entry
from .forms import TopicForm, EntryForm
Create your views here.
def index(request):
"""学习笔记的主页"""
return render(request, 'learning_logs/index.html')
def topics(request):
"""显示所有的主题"""
topics = Topic.objects.order_by('date_added')
context = {'topics': topics}
return render(request, 'learning_logs/topics.html', context)
def topic(request, topic_id):
"""显示单个主题及其所有的条目"""
topic = Topic.objects.get(id=topic_id)
entries = topic.entry_set.order_by('-date_added')
context = {'topic': topic, 'entries': entries}
return render(request, 'learning_logs/topic.html', context)
def new_topic(request):
"""添加新主题"""
if request.method != 'POST':
#未提交数据： 创建一个新表单
form = TopicForm()
else:
form = TopicForm(request.POST)
if form.is_valid():
form.save()
return HttpResponseRedirect(reverse('learning_logs:topics'))
context = {'form': form}
return render(request, 'learning_logs/new_topic.html', context)
def new_entry(request, topic_id):
"""在特定的主题中添加新条目"""
topic = Topic.objects.get(id=topic_id)
if request.method != 'POST':
#未提交数据，创建一个空表单
form = EntryForm()
else:
#POST提交的数据，对数据进行处理
form = EntryForm(data=request.POST)
if form.is_valid():
new_entry = form.save(commit=False)
new_entry.topic = topic
new_entry.save()
return HttpResponseRedirect(reverse('learning_logs:topic',
args=[topic_id]))
context = {'topic': topic, 'form': form}
return render(request, 'learning_logs/new_entry.html', context)
def edit_entry(request, entry_id):
"""编辑既有条目"""
entry = Entry.objects.get(id=entry_id)
topic = entry.topic
if request.method != 'POST':
#初次请求，使用当前条目填充表单
form = EntryForm(instance=entry)
else:
#POST提交的数据，对数据进行处理
form = EntryForm(instance=entry, data=request.POST)
if form.is_valid():
form.save()
return HttpResponseRedirect(reverse('learning_logs:topic',
args=[topic.id]))
context = {'entry': entry, 'topic': topic, 'form': form}
return render(request, 'learning_logs/edit_entry.html', context)
