Django中的验证码

1、View

def verification_code(request):
    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)
    im = Image.new('RGB', (width, height), (255, 255, 255))
    # 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
    str1 = 'ABCD123EFGHIJK456LMNOPQRS789TUVWXYZ0'
    # 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('simsun.ttc', 23)
    # 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
    # 创建内存读写的对象
    buf = BytesIO()
    # 将图片保存在内存中，文件类型为png
    im.save(buf, 'png')

    # 放入session中
    request.session['verificationcode'] = rand_str
    request.session.set_expiry(0)

    return HttpResponse(buf.getvalue(), 'image/png')

2、Template

<td>验证码</td>
<td><input type="text" name="verificationcode"/></td> 
<td><img src="/user/verification_code" alt="验证码" id="verificationcode"/></td>

<script>
    window.onload = function(){
        src = "/user/verification_code?n="
        code = document.getElementById("verificationcode")
        //为验证码添加click事件
        code.onclick = function(){
            code.src = src + new Date().getTime()
        }
    }
</script>