文件目录结构

创建项目

 django-admin startproject myweb

创建应用

python manage.py startapp myapp

修改myweb代码

myweb --> url.py

这里用myapp的urls.py 所以myweb urls.py需要 from django.urls import include

"""myweb URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/2.2/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  path('', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.urls import include, path
    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
"""
from django.contrib import admin
from django.urls import path,include

urlpatterns = [
    #path('admin/', admin.site.urls),
    path('', include("myapp.urls")),
]

myweb --> settings.py

"""
Django settings for myweb project.

Generated by 'django-admin startproject' using Django 2.2.24.

For more information on this file, see
https://docs.djangoproject.com/en/2.2/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/2.2/ref/settings/
"""

import os

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/2.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = '*^m)_4z9q$m!it7*=wm$%^snry%p!pc^^!fg5ho=496manc-ff'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = ['*']


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'myapp',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'myweb.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR,'templates')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'myweb.wsgi.application'


# Database
# https://docs.djangoproject.com/en/2.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}


# Password validation
# https://docs.djangoproject.com/en/2.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/2.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/2.2/howto/static-files/

STATIC_URL = '/static/'

修改myapp代码

myapp --> urls.py（自行创建）

from django.urls import path
from . import views
from myapp.views import MyView
urlpatterns = [
    path('', views.index, name="index"), # 首页
    path('resp01', views.resp01, name="resp01"), # 首页 # 一个简单的视图
    path('resp02', views.resp02, name="resp02"), # 返回一个错误
    path('resp03', views.resp03, name="resp03"), # 重定向
    path('resp04', MyView.as_view(), name="resp04"), # 基本类的视图
    path('resp05', views.resp05, name="resp05"), # 响应json数据
    path('resp06', views.resp06, name="resp06"), # Cookie的使用
    path('resp07', views.resp07, name="resp07"), # 测试request请求对象
    path('resp08', views.verifycode, name="resp08"),  # 测试验证码
]

myapp --> views.py

from django.shortcuts import render
from django.http import HttpResponse,HttpResponseNotFound,Http404,JsonResponse
from django.shortcuts import redirect
from django.urls import reverse
from django.views import View
# Create your views here.
def index(request):
    return render(request, "myapp/index.html")

def resp01(request):
    return HttpResponse("<h3>一个简单的视图</h3>")

def resp02(request):
    # 直接返回一个404，没有去加载404的模板页面
    return HttpResponseNotFound("<h3>404</h3>")

    # 可以直接返回一个status状态码
    #return HttpResponse(status=403)

    # 返回一个404的错误页面
    #raise Http404("Poll does not exist")

# 重定向
def resp03(request):
    # redirect重定向 reverse方向解析url地址
    #return redirect(reverse('resp01'))

    # 执行一段js代码，用js进行重定向
    return HttpResponse('<script>alert("跳转成功");location.href = "/resp01";</script>')

    # 加载一个提醒信息的跳转页面
    # context = {'info':'数据添加成功','u':'/resp01'}
    # return render(request, 'info.html',context)

# 视图类的定义
class MyView(View):
    def get(self, request, *args, **kwargs):
        return HttpResponse('hello, Views!')


# json 数据的响应
def resp05(request):
    data = [
        {'id':1001,'name':'zhangshan','age':20},
        {'id':1002,'name':'lisi','age':22},
        {'id': 1003,'name':'xiaoshan','age': 22},
    ]
    return JsonResponse({"data":data})


# cookie的使用
def resp06(request):
    # 读取
    m = request.COOKIES.get('num',None)
    if m:
        m = int(m) + 1
    else:
        m = 1

    # 获取当前的响应对象
    response = HttpResponse('cookie记录的计数器值:'+str(m))

    # print(request.COOKIES.get('a',None))
    # 使用响应对象进行cookie的设置
    response.set_cookie('num',m)

    # 返回响应对象
    return response


# 测试request对象
def resp07(request):
    print("请求路径",request.path)
    print("请求方法",request.method)
    print("请求编号",request.encoding)
    #print(request.GET)
    print(request.GET['id'])
    print(request.GET.get('name'))
    print(request.GET.get('age',0))
    return HttpResponse("测试request请求对象")


# 验证码的输出
def verifycode(request):
    # 引入绘图模块
    from PIL import Image, ImageDraw, ImageFont
    # 引入随机函数模块
    import random
    # 定义变量，用于画面的背景色，宽，高
    bgcolor = (random.randrange(20, 100),random.randrange(20, 100), 255)
    width = 100
    height = 25
    # 创建画面对象
    im = Image.new('RGB', (width, height),bgcolor)
    # 创建画面对象
    draw = ImageDraw.Draw(im)
    # 调用画笔的point()函数绘制躁点
    for i in range(0, 100):
        xy = (random.randrange(0, width), random.randrange(0, height))
        fill = (random.randrange(0, 255), 255, random.randrange(0, 255))
        draw.point(xy, fill=fill)
    # 定义验证码的备选值
    str1 ='ABCD123EFGHIJK456LMNOPQRS789TUVWXYZO'
    # 随机选取4个值作为验证码
    rand_str = ''
    for i in range(0, 4):
        rand_str += str1[random.randrange(0, len(str1))]
    # 构造字体对象
    font = ImageFont.truetype('static/ariali.ttf', 23)
    #font = ImageFont.load_default().font # 默认使用系统字体
    # 构造字体颜色
    fontcolor = (255, random.randrange(0,255), random.randrange(0,255))
    # 绘制4个字
    draw.text((5,2), rand_str[0], font=font, fill=fontcolor)
    draw.text((25,2), rand_str[1], font=font, fill=fontcolor)
    draw.text((50,2), rand_str[2], font=font, fill=fontcolor)
    draw.text((75,2), rand_str[3], font=font, fill=fontcolor)
    # 释放画笔
    del draw
    # 存入session，用于做进一步验证
    #request.session['verifycode'] = rand_str
    # 内存文件操作
    """
    python2的为
    # 内存文件操作
    import cStringIO
    buf = cStringIO.StringIO()
    """
    # 内存文件操作-->此方法为pyhton3
    import io
    buf = io.BytesIO()
    # 将图片保存在内存中，文件类型为png
    im.save(buf, 'png')
    # 将内存中的图片数据返回给客户端，MIME类型为图片png
    return HttpResponse(buf.getvalue(), 'image/png')

创建static 目录，字体获取可以从window font文件夹下获取

?创建 templates--> myapp--> index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Django的视图层</title>
</head>
<body>
    <h2>Django的视图层</h2>
    <ul>
        <li><a href="{% url 'resp01' %}">1.一个简单的视图</a> </li>
        <li><a href="{% url 'resp02' %}">2.返回404</a> </li>
        <li><a href="{% url 'resp03' %}">3.重定向</a> </li>
        <li><a href="{% url 'resp04' %}">4.基于类的操作</a> </li>
        <li><a href="{% url 'resp05' %}">5.响应json格式</a> </li>
        <li><a href="{% url 'resp06' %}">6.Cookies的使用</a> </li>
        <li><a href="{% url 'resp07' %}?id=100&name=zhangsan&age=22">7.request请求</a> </li>
        <li><a href="{% url 'resp08' %}">8.验证码的输出</a> </li>

    </ul>

    <img id='verifycode' src="{% url 'resp08' %}" alt="CheckCode" />

</body>
</html>