python web框架Flask——图形验证码及验证码的动态刷新

主目录/utils/captcha/__init__.py

import random
import string

# Image:一个画布
# ImageDraw:一个画笔
# ImageFont:画笔的字体
from PIL import Image, ImageDraw, ImageFont


# Captcha验证码
class Captcha(object):
    # 生成4位数的验证码
    numbers = 4
    # 验证码图片的宽度和高度
    size = (100, 30)
    # 验证码字体大小
    fontsize = 25
    # 加入干扰线的条数
    line_number = 2

    # 构建一个验证码源文本
    SOURCE = list(string.ascii_letters)
    for index in range(0, 10):
        SOURCE.append(str(index))

    # 用来绘制干扰线
    @classmethod
    def __gene_line(cls, draw, width, height):
        begin = (random.randint(0, width), random.randint(0, height))
        end = (random.randint(0, width), random.randint(0, height))
        draw.line([begin, end], fill=cls.__gene_random_color(), width=2)

    # 用来绘制干扰点
    @classmethod
    def __gene_points(cls, draw, point_chance, width, height):
        # 大小限在【0， 100】中
        chance = min(100, max(0, int(point_chance)))
        for w in range(width):
            for h in range(height):
                tmp = random.randint(0, 100)
                if tmp > 100 - chance:
                    draw.point((w, h), fill=cls.__gene_random_color())

    # 生成随机颜色
    @classmethod
    def __gene_random_color(cls, start=0, end=255):
        random.seed()
        return (random.randint(start, end),
                random.randint(start, end),
                random.randint(start, end))

    # 随机选择一个字体
    @classmethod
    def __gene_random_font(cls):
        fonts = [
            "PAPYRUS.TTF",
            "CENTAUR.TTF",
            "Inkfree.ttf",
            "verdana.ttf",
        ]
        font = random.choice(fonts)
        return "utils/captcha/"+font

    # 用来随机生成一个字符串（包括英文和数字）
    @classmethod
    def gene_text(cls, numbers):
        # numbers是生成验证码的位数
        return " ".join(random.sample(cls.SOURCE, numbers))

    # 生成验证码
    @classmethod
    def gene_graph_captcha(cls):
        # 验证码图片的宽高
        width, height = cls.size
        # 创建图片
        image = Image.new("RGBA", (width, height), cls.__gene_random_color(0, 100))
        # 验证码的字体
        font = ImageFont.truetype(cls.__gene_random_font(), cls.fontsize)
        # 创建画笔
        draw = ImageDraw.Draw(image)
        # 生成字符串
        text = cls.gene_text(cls.numbers)
        # 获取字体的尺寸
        font_width, font_height = font.getsize(text)
        # 填充字符串
        draw.text(((width-font_width)/2, (height-font_height)/2),
                  text, font=font, fill=cls.__gene_random_color(150, 255))
        # 绘制干扰线
        for x in range(0, cls.line_number):
            cls.__gene_line(draw, width, height)
        # 绘制干扰点
        cls.__gene_points(draw, 10, width, height)
        with open("captcha.png", "wb") as fp:
            image.save(fp)
        return text, image

主目录/common/views.py

@bp.route("/captcha")
def graph_captcha():
    """
    使用定义好的图形验证码类，来制作验证码
    以验证码为键、验证码为值（为了用户的体验，让其忽略大小写）存储在redis缓存中
    通过BytesIO字节流的方式保存和访问图片
    :return: 图片响应
    """
    # 获取验证码
    text, image = Captcha.gene_graph_captcha()
    cpcache.set(text.lower(), text.lower())

    # BytesIO:字节流
    out = BytesIO()
    # 保存图片
    image.save(out, "png")
    # 存储完图片，将文件的指针指向文件头，使下次保存图片能覆盖前面保存的图片，节省空间
    out.seek(0)
    # 访问图片，并将其作为一个响应返回给前台
    resp = make_response(out.read())
    resp.content_type = "image/png"
    return resp

<div class="form-group">
    <div class="input-group">
        <input type="text" class="form-control" name="graph_captcha" placeholder="图形验证码">
        <span class="input-group-addon captcha-addon">
            <img id="captcha-img" class="captcha-img" src="{{ url_for("common.graph_captcha") }}" alt="">
        </span>
    </div>
</div>

这个文件放在公共的目录下就可以了

var cpparam = {
    setParam: function(href, key, value){
        //重新加载整个页面
        var isReplaced = false;
        var urlArray = href.split("?");
        if(urlArray.length > 1){
            var queryArray = urlArray[1].split("&");
            for(var i=0; i < queryArray.length; i++){
                var paramArray = queryArray[i].split("=");
                if(paramArray[0] == key){
                    paramArray[1] = value;
                    queryArray[i] = paramArray.join("=");
                    isReplaced = true;
                    break;
                }
            }
            if(!isReplaced){
                var params = {};
                params[key] = value;
                if(urlArray.length > 1){
                    href = href + "$" + $.param(params);
                }else{
                    href = href + "?" + $.param(params);
                }
            }else{
                var params = queryArray.join("&");
                urlArray[1] = params;
                href = urlArray.join("?");
            }
        }else{
            var param = {};
            param[key] = value;
            if(urlArray.length > 1){
                href = href + "$" + $.param(param);
            }else{
                href = href + "?" + $.param(param);
            }
        }
        return href;
    }
};

$(function(){
   $("#captcha-img").on("click", function(){
       var self = $(this);
       var src = self.attr("src");
       var newsrc = cpparam.setParam(src, "xx", Math.random());
       self.attr("src", newsrc);
   });
});