AI-CBV写法

CBV固定样式

#url.py

from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^login/', views.Loginview.as_view()), #CBV格式，Loginview是类名
]

# views.py

from django.shortcuts import render,HttpResponse
from django.views import View
# Create your views here.
class Loginview(View): #里边可以封装很多方法
    def get(self,request):
        return render(request,"login.html",locals())

    def post(self,request):
        return HttpResponse("post")

#login.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.css" rel="stylesheet">
</head>
<body>
<form action="" method="post">
    {% csrf_token %}
    用户名：<input type="text" name="user">
    密码：<input type="password" name="pwd">
    <button type="submit">提交</button>
</form>
</body>
</html>

CBV源码解析

#1.从url开始执行
urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^login/', Views.Loginview.as_view()), #CBV格式，Loginview是类名 
]

#2.url(r'^login/', views.Loginview.as_view()) 代表在Loginview继承的View类中找as_view方法

def as_view(cls, **initkwargs):
    def view(request, *args, **kwargs):
        self = cls(**initkwargs)
        if hasattr(self, 'get') and not hasattr(self, 'head'):  # self,即Login_View对象
            self.head = self.get
        self.request = request
        self.args = args
        self.kwargs = kwargs
        return self.dispatch(request, *args, **kwargs)
    return view
# 3.调用as_view方法时，返回了view,相当于
url(r'^login/', Views.view)

# 4.一旦用户get访问login,相当于给view传参view(request)
def view(request, *args, **kwargs):
    self = cls(**initkwargs)  #5.cls为当前类的实例化对象，即LoginView的实例化对象
    if hasattr(self, 'get') and not hasattr(self, 'head'):  # self,即Login_View对象
        self.head = self.get
    self.request = request
    self.args = args
    self.kwargs = kwargs
    return self.dispatch(request, *args, **kwargs)  #6.表示从LoginView的实例化对象中找dispatch方法

# 7.找不到dispatch方法，就在View中找
class Loginview(View): #里边可以封装很多方法
    def get(self,request):
        return render(request,"login.html",locals())

# 8. 找到dispatch方法，
class View(object):

    http_method_names = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']

    def dispatch(self, request, *args, **kwargs):
        if request.method.lower() in self.http_method_names:
            # handler表示get、post等
            handler = getattr(self, request.method.lower(), self.http_method_not_allowed) #8.self不在request.method.lower()中，
                                                                                     # 就使用self.http_method_not_allowed进行报错处理
        else:
            handler = self.http_method_not_allowed
        return handler(request, *args, **kwargs) #9.执行handler(get()、post()等方法)
    
# 10.执行get等方法，返回前端页面，完毕
class Loginview(View): #里边可以封装很多方法
    def get(self,request):
        return render(request,"login.html",locals())

AI-CBV写法

AI-CBV写法

CBV固定样式

CBV源码解析

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