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), random.randrange(20, 100))
  width = 100
  height = 50
  #创建画面对象
  im = Image.new('RGB', (width, height), bgcolor)
  #创建画笔对象
  draw = ImageDraw.Draw(im)
  #调用画笔的point()函数绘制噪点
  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
  str = '1234567890QWERTYUIOPASDFGHJKLZXCVBNMqwertyuiopasdfghjklzxcvbnm'
  #随机选取4个值作为验证码
  rand_str = ''
  for i in range(0, 4):
    rand_str += str[random.randrange(0, len(str))]
  #构造字体对象
  font = ImageFont.truetype(r'C:\Windows\Fonts\AdobeArabic-Bold.otf', 40)
  #构造字体颜色
  fontcolor1 = (255, random.randrange(0, 255), random.randrange(0, 255))
  fontcolor2 = (255, random.randrange(0, 255), random.randrange(0, 255))
  fontcolor3 = (255, random.randrange(0, 255), random.randrange(0, 255))
  fontcolor4 = (255, random.randrange(0, 255), random.randrange(0, 255))
  #绘制4个字
  draw.text((5, 2), rand_str[0], font=font, fill=fontcolor1)
  draw.text((25, 2), rand_str[1], font=font, fill=fontcolor2)
  draw.text((50, 2), rand_str[2], font=font, fill=fontcolor3)
  draw.text((75, 2), rand_str[3], font=font, fill=fontcolor4)
  #释放画笔
  del draw

  #内存文件操作
  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
  response = HttpResponse(buf.getvalue(), 'image/png')

  #将验证码的值写入cookie，以被前端浏览器验证验证码
  # response.set_cookie("verifycode", rand_str)

  # 存入session，用于做进一步验证
  request.session['verifycode'] = rand_str

  return response

def login(request):
  if request.method == "GET":
    infoStr = "<h1>sunck is a good man</h1>"
    # infoStr = "<script>alert('sunck good')</script>"
    return render(request, "login.html", {"infoStr":infoStr})
  else:
    #判断验证码
    verifycode = request.POST.get("verifycode")
    if not verifycode.upper() == request.session.get("verifycode").upper():
      return redirect("/login/")

    username = request.POST.get("username")
    password = request.POST.get("password")
    if username == "sunck" and password == "sunck1999":
      return redirect("/index/")
    else:
      return redirect("/login/")

from django.utils.deprecation import MiddlewareMixin
from django.shortcuts import redirect


class VerifycodeMiddleware(MiddlewareMixin):
  def process_request(self, request):
    print("***************", request.path)
    if request.path == "/login/" and request.method == "POST":
      # 判断验证码
      verifycode = request.POST.get("verifycode")
      if not verifycode.upper() == request.session.get("verifycode").upper():
        return redirect("/login/")

'myApp.middlewares.verifycodeMiddleware.VerifycodeMiddleware'