2021-05-17 给二维码图片添加提示文字

以你之姓@ 2023-01-22 04:52 75阅读 0赞

需求：

判断当前浏览器是否为微信，是的话挑起微信支付，不是的话，显示二维码图片并提示用户到微信中打开

效果图：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pha2V0NTIxOTk5OQ_size_16_color_FFFFFF_t_70][]

大致代码如下：

1. 判断是否微信

# toolbox.py
    from typing import Any
    
    
    class UserAgent:
        def __init__(self, user_agent: str = '', request: Any = None):
            if request is not None:
                try:
                    user_agent = request.headers.get('user-agent', '')  # For Sanic
                except AttributeError:
                    user_agent = request.META.get('HTTP_USER_AGENT', '')  # Django
            self.user_agent = user_agent
    
        @property
        def is_alipay(self) -> bool:
            return "AlipayClient/" in self.user_agent
    
        @property
        def is_wechat(self) -> bool:
            return "MicroMessenger/" in self.user_agent
    
        @property
        def is_qq(self) -> bool:
            return " QQ/" in self.user_agent
    
        @property
        def scan_type(self) -> str:
            if self.is_wechat or self.is_qq:
                return "wechat"
            if self.is_alipay:
                return "alipay"
            return "unknown"

2. 给图片加文字 （参考了这篇文章并做了一些修改：[https://blog.csdn.net/weixin\_41896770/article/details/105557758][https_blog.csdn.net_weixin_41896770_article_details_105557758]）

# image_text.py
    """
    给图片（如二维码）添上文字
    
    Usage::
        >>> from xxx import deco_image
        >>> deco_image(image_path, text)  # 替换旧图片
        >>> deco_image(image_path, text, new_path, color='red')  # 保留旧图片并指定文字颜色
    """
    from pathlib import Path
    from typing import Optional, Tuple, Union
    
    from PIL import Image, ImageDraw, ImageFont  # pip install pillow
    
    TIP = "请用微信扫码支付\n或分享到微信中打开"
    
    
    # 获取图片宽度
    def get_img_width(fname) -> int:
        return Image.open(fname).size[0]
    
    
    # 获取图片高度
    def get_img_height(fname) -> int:
        return Image.open(fname).size[1]
    
    
    # 给图片加文字
    # 生成blank_img空白图片，加上文字之后生成新图片或覆盖旧图, 宽度为origin_img原始图片的宽度
    
    MARGIN_LEFT, MARGIN_TOP = 50, 15
    FONT_SIZE = 22
    FONT_COLOR = "red"
    
    
    def gen_text_img(
        origin_img: Union[Path, str],
        text: str,
        img_path=None,
        color=FONT_COLOR,
        font_size: int = FONT_SIZE,
        margin_left: int = MARGIN_LEFT,
        margin_top: int = MARGIN_TOP,
        blank_img=None,
        font_path: Optional[str] = None,
        show_img: bool = False,
    ) -> Union[Path, str]:
        width = get_img_width(origin_img)
        if blank_img is None:
            blank_img = Path(f"/tmp/blank-{width}.png")
        elif isinstance(blank_img, str):
            blank_img = Path(blank_img)
        if not blank_img.exists():
            Image.new("RGB", (width, 70), (255, 255, 255)).save(blank_img)
        im = Image.open(blank_img)
        draw = ImageDraw.Draw(im)
        if font_path is None:
            # font_path = r"C:\Windows\Fonts\simsun.ttc"
            # font_path = "/System/Library/Fonts/Supplemental/Songti.ttc"
            font_path = "/usr/share/fonts/truetype/windows-font/Songti.ttc"
        fnt = ImageFont.truetype(font_path, font_size)
        draw.text((margin_left, margin_top), text, fill=color, font=fnt)
        if img_path is None:
            img_path = Path(origin_img)
            img_path = img_path.with_name(f"{img_path.stem}-{len(text)}{img_path.suffix}")
        im.save(img_path)
        if show_img:
            im.show()
        return img_path
    
    
    # 拼接图片，把上面生成的文字图片拼接到原图上面
    # 生成一张宽度一致，高度为两张图片之和的空白长图
    # 分别打开图片进行粘贴到空白长图里面
    
    def join_imgs(text_img, origin_img, new_path=None) -> None:
        w = get_img_width(text_img)
        fh = get_img_height(text_img)
        oh = get_img_height(origin_img)
    
        blank_long_img = Image.new("RGBA", (w, fh + oh))  # 空白长图
    
        font_img = Image.open(text_img).resize((w, fh), Image.ANTIALIAS)
        blank_long_img.paste(font_img, (0, 0))
    
        img1 = Image.open(origin_img).resize((w, oh), Image.ANTIALIAS)
        blank_long_img.paste(img1, (0, fh))
        if new_path is None:
            new_path = origin_img
        blank_long_img.save(new_path)
        blank_long_img.show()
    
    
    def deco_image(
        fpath: Union[Path, str],  # 图片路径
        text: str = TIP,  # 要添加的文字
        new_path: Union[Path, str, None] = None,  # 新图片要保存的路径（默认覆盖原图）
        color: Union[str, Tuple[int, int, int]] = FONT_COLOR,  # 文字颜色
        font_size: int = FONT_SIZE,  # 文字高度
        margin_left: int = MARGIN_LEFT,
        margin_top: int = MARGIN_TOP,
    ) -> None:
        text_img = gen_text_img(
            fpath,
            text,
            color=color,
            font_size=font_size,
            margin_left=margin_left,
            margin_top=margin_top,
        )
        join_imgs(text_img, fpath)

3. 如果系统缺字体，那么需要去下载

sudo mkdir /usr/share/fonts/truetype/windows-font
    sudo chmod 777 /usr/share/fonts/truetype/windows-font
    cd /usr/share/fonts/truetype/windows-font
    wget https://gitee.com/waketzheng/carstino/attach_files/703450/download/Songti.ttc  # 该文件比较大，有66.9MB

4. 调起支付或生成图片

from pathlib import Path
    from hashlib import md5
    
    import qrcode  # pip install qrcode
    from sanic import Blueprint
    from sanic.log import logger
    from sanic.request import Request
    from sanic.response import json
    
    from .models import Order
    from .image_text import deco_image
    from .toolbox import UserAgent
    from .utils import async_http_post, get_host
    from .consts import URL_PREFIX, WX_PAY_URL
    
    
    bp = Blueprint("epay", url_prefix=URL_PREFIX)
    
    async def get_qf_mch(community):
        pass
    
    
    @bp.route("/pay-link", methods=["POST"])
    async def pay_link(request: Request):
        requires, data = ["bills", "total", "next"], request.json
        logger.info(f"{request.url = } ;  {request.json = }")
        # 已经1分钟内生成过对应订单的，直接去支付
        content = request.body + f"{datetime.now():%y%m%d%H%M%S}".encode()
        body = md5(content).hexdigest()
        if not (order := await Order.filter(body=body).first()):
            order = await new_pay_order(origin, data, request, body)
        mchid, mch_name = await get_qf_mch(order.community)
        if mchid:
            host = get_host(request.headers)
            if not UserAgent(request=request).is_wechat:
                # 故判断当前是否在微信里，如果不是就直接生成二维码
                frontend_url = data["next"]
                fpath = "payit/" + md5(frontend_url.encode()).hexdigest() + ".png"
                if not (p := BASE_DIR / "media" / fpath).parent.exists():
                    p.parent.mkdir(parents=True)
                qrcode.make(frontend_url).save(p)
                deco_image(p)
                img_url = host + URL_PREFIX + "/media/" + fpath
                return json({"payUrl": img_url})
            return json(qf_pay_it(mchid, mch_name, order, host=host))
        url = WX_PAY_URL
        if not (request_data := order.post_data).get("mch"):
            request_data.update(mch=1)  # 未配置支付的,先用1
        res = await async_http_post(url, request_data)
        try:
            res_json = res.json()
        except Exception as e:
            logger.error(f"{e = }; {url = }; {order.post_data=}; {res.content = }")
        return json(res_json)

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pha2V0NTIxOTk5OQ_size_16_color_FFFFFF_t_70]: /images/20221020/b162f6306ff94525abbf9c6452877c06.png
[https_blog.csdn.net_weixin_41896770_article_details_105557758]: https://blog.csdn.net/weixin_41896770/article/details/105557758