Django 视图

一个视图函数（类）简称视图，是一个简单的Python 函数（类），包含的是业务逻辑，它接受Web请求并且返回Web响应。
一般放在 project 或 APP 的 views.py 中

获取用户请求数据

request.environ 中封装了所有用户请求信息

request.GET
request.POST
request.FILES      # 获取上传文件
request.COOKIES    # 获取COOKIES
request.path_info    # 获取当前请求URL
request.environ['HTTP_USER_AGENT']    # 获取用户设备信息

示例：
html:

<form action="/login.html" method="post">
    <input type="text" name="user_name" placeholder="User Name" required/>
    <input type="password" name="password" placeholder="Password" required/>
</form>

views.py:

if request.method == 'POST':
    username = request.POST.get('user_name')
    password = request.POST.get('password')

checkbox等多选的内容（列表）

request.POST.getlist()

示例：
html:

<form method="post" action="/test/">
    <p>1:<input type="checkbox" name="choose" value="1"></p>
    <p>2:<input type="checkbox" name="choose" value="2"></p>
    <p>3:<input type="checkbox" name="choose" value="3"></p>
    <input type="submit">
</form>

views.py:

if request.method == 'POST':
    res = request.POST.getlist('gender', None)
    print(res)

输出结果：
['2', '3']

上传文件

示例：
html:

<form method="post" action="/test/" enctype="multipart/form-data">
    <input type="file" name="fname">
    <input type="submit">
</form>

views.py

import os

if request.method == 'POST':
    file = request.FILES.get('fname', None)		# 获取上传的文件
    print(file.name, file.size)
    file_path = os.path.join('upload', file.name)	# 找到储存文件的位置
    f = open(file_path, 'wb')	# 创建空文件
    for i in file.chunks():		# 循环读取文件
        f.write(i)	# 循环写入
    f.close()

之后文件就上传到了项目目录下 upload 中

FBV & CBV

function base view
class base view

url.py:

from django.urls import path

urlpatterns = [
    path('login/', views.login),
    path('home/', views.Home.as_view()),
]

views.py:

from django.shortcuts import HttpResponse
from django.views import View

def login(request):
	if request.method == 'GET':
		return HttpResponse(get)
    if request.method == 'POST':
    	return HttpResponse(post)


class Home(View):
    # 先执行的函数
    def dispatch(self, request, *args, **kwargs):
        # 获取请求之前
        print('before')
        # 调用父类中的dispatch，获取请求
        result = super(Home, self).dispatch(request, *args, **kwargs)
        # 获取请求之后
        print('after')
        return result

    @staticmethod
    def get(self, request):
    	print(request.method)
        return HttpResponse(get)

    @staticmethod
    def post(self, request):
        print(request.method)
        return HttpResponse(post)