摘要：類視圖簡介視圖是一個可調用的對象，它接收一個請求然后返回一個響應，這個可調用對象可以不只是函數，提供一些可以用作視圖的類基于類的視圖使用對象實現視圖，它提供除函數視圖之外的另外一種方式屬性添加未知的請求方法方法將類視圖轉換成可被調用的函數視

視圖是一個可調用的對象，它接收一個請求然后返回一個響應，這個可調用對象可以不只是函數，Django提供一些可以用作視圖的類
基于類的視圖使用Python 對象實現視圖，它提供除函數視圖之外的另外一種方式

屬性

http_method_names：添加未知的請求方法

方法

as_view()：將類視圖轉換成可被調用的函數視圖
dispatch()： 根據請求去匹配http_method_names下的對應函數去處理請求
http_method_not_allowed()：返回405錯誤

實例

from django.views import View
class IndexView(View):
    http_method_names = ["get", "post", "put", "patch", "delete", "head", "options", "trace","list"]
    def get(self,request,*args,**kwargs):
        return HttpResponse(IndexView)

    def post(self,request,*args,**kwargs):
        data = request.POST
        return HttpResponse(data)
    #需要將list方法加入 http_method_names，否則會經過，dispatch，http_method_not_allowed()：返回405錯誤
    def list(self,request,*args,**kwargs):
        return HttpResponse("ListView")
請求方式：
In [27]: import requests                                                                
In [28]: url = "http://192.168.33.10:8080/dashboard/index/"                             
In [29]: res = requests.request("list",url)                                             
In [30]: res.content                                                                    
Out[30]: b"ListView"

數據準備

In [3]: from django.contrib.auth.models import User
In [4]: for n in range(1,101): 
...:     User.objects.create_user("wanghui-{}".format(n),"wanghui-{}@alibaba.com".format(n),"123456") 
In [5]: User.objects.all()[1:10]      

類視圖

class UserView(View):
    #http_method_names = ["get", "post", "put", "patch", "delete", "head", "options", "trace","list"]
    def get(self,request,*args,**kwargs):
      #展示數據
        # queryset = User.objects.all()
        # return HttpResponse(queryset)
        try:
            page = int(request.GET.get("page"))
        except:
            page = 1
        if page < 1:
            page = 1
        per = 10
        end = page * per
        start = end - per
        queryset = User.objects.all()[start:end]
        data = [{"id":user.id,"username":user.username,"email":user.email} for user in queryset]
        return JsonResponse(data,safe=False)

class Paginator(object_list, per_page, orphans=0, allow_empty_first_page=True)
屬性
- Paginator.count 所有頁面的objects總數
- Paginator.num_pages 頁面總數
- Paginator.page_range 頁碼的范圍，從1開始，例如[1, 2, 3, 4]
方法
- Paginator.page(number) 返回一個page對象,number， 當前顯示的是第幾頁

Page對象

class Page(object_list, number, paginator)

方法
- Page.has_next() 如果有下一頁，返回True
- Page.has_previous() 如果有上一頁，返回 True
- Page.has_other_pages() 如果有上一面或下一頁，返回True
- Page.next_page_number() 返回下一頁的頁碼.如果不存在,拋出InvalidPage異常
- Page.previous_page_number() 返回上一頁的頁碼.如果不存在,拋出InvalidPage異常
- Page.start_index() 返回當前頁上的第一個對象，相對于分頁列表的所有對象的序號
- Page.end_index() 返回當前頁上的最后一個對象，相對于分頁列表的所有對象的序號

from django.core.paginator import Paginator
class UserViewV2(View):
    def get(self,request,*args,**kwargs):
        queryset = User.objects.all()
        paginator = Paginator(queryset,10)
        try:
            page = int(request.GET.get("page"))
        except:
            page = 1
        if page < 1:
            page = 1
        page = paginator.page(page)
        data = [{"id":user.id,"username":user.username,"email":user.email} for user in page.object_list]
        return JsonResponse(data,safe=False)

    def post(self,request,*args,**kwargs):
        username = request.POST.get("username")
        userpass = request.POST.get("userpass")
        email = request.POST.get("email")
        if not username or userpass or not email:
            return JsonResponse({"errormsg":"參數有誤！"})
        user = User.objects.create(username,email,userpass)
        return JsonResponse({"id":user.id,"username":user.username,"email":user.email})

請求方式

In [1]: import requests                                                                     
In [2]: url = "http://192.168.33.10:8080/dashboard/userview/"                
In [3]: data = {}                                                                                         
In [4]: data["username"] = "zhangsan"                                                     
In [5]: data["userpass"] = "123456"                                                           
In [6]: data["email"] = "zhangsan@alibaba.com"                                     
In [7]: requests.post(url,data)                                                                 
Out[7]: