php生成海报图出现图片损坏的问题

简介

 近年小程序、微信发展迅速。微信、微博病毒式传播使用户从传统的APP上向即扫即用、无需安装的小程序上转化。而微信公众号、小程序的迅速发展离不开转发、二维码分享。

 但是二维码形式单一，对用户来说毫无吸引力。纯粹依靠‘吆喝、金钱、礼物吸引’方式已经变得愈来愈无价值。

 对于’视觉动物’和大部分用户来说，精美的图片加上二维码的组合更具有吸引力。

php生成海报图前提条件

• gd库扩展

上代码

生成方法

// 生成方法
private function createPoster($data)
    {
        $poster = new Poster();
        //创建画布
        $im = $poster->createTrueColor(672, 1060);
        //字体文件
        $font_file = $this->typeface;
        // 商品图片
        $goodsImg = $poster->createImgBoard($im, $data['goodsPath'], 0, 0, 672, 668);
        //二维码
        $codeImg = $poster->createImgBoard($im, $data['qrcode'], 410, 710, 225, 225);
        //headimg
        $headImg = $poster->createImgBoard($im, $data['headimg'], 46, 942, 65, 65);
        //btnimg
        $btnimg = $poster->createImgBoard($im, $data['btn'], 420, 960, 220, 48);

        // 价格
        $price_font = ImageColorAllocate($im, 248, 6, 74);
        imagettftext($im, 25, 0, 41, 759, $price_font, $font_file, '¥');
        imagettftext($im, 38, 0, 60, 760, $price_font, $font_file, $data["price"]);

        // 商品名称
        $goodsName = trim(mb_substr($data['title'], 0, 20));
        $good_font = ImageColorAllocate($im, 1, 1, 1);
        imagettftext($im, 24, 0, 40, 820, $good_font, $font_file, $poster->AutoWrap(12, 0, $font_file, $goodsName, 160));

        // 昵称
        $nickname = trim(mb_substr($data['nickname'], 0, 8));
        $nick_font = ImageColorAllocate($im, 109, 114, 120);
        imagettftext($im, 16, 0, 130, 965, $nick_font, $font_file, $poster->AutoWrap(12, 0, $font_file, $nickname, 80));
        imagettftext($im, 16, 0, 130, 1000, $nick_font, $font_file, $data['time']);
        ob_clean();
        ob_end_clean();
        // 输出图片
        $poster->lookImg($im);

        //释放空间
        imagedestroy($im);
        imagedestroy($btnimg);
        imagedestroy($goodsImg);
        imagedestroy($codeImg);
        imagedestroy($headImg);
        // 删除本地二维码
        Qrcode::deleteCode($data['qrcode']);
    }

实现类

// 具体类
<?php
namespace app\library;

/**
 *  生成海报图
 * @author daichongweb
 * @url daichongweb.cn,daichongweb.com
 */
class Poster
{
    /**
     * 从图片文件创建Image资源
     * @param $file 图片文件，支持url
     * @return bool|resource    成功返回图片image资源，失败返回false
     */
    public function createImageFromFile($file)
    {
        if (preg_match('/http(s)?:\/\//', $file)) {
            $fileSuffix = self::getNetworkImgType($file);
        } else {
            $file_info = getimagesize($file);
            $fileSuffix = $file_info[2];
            // $fileSuffix = pathinfo($file, PATHINFO_EXTENSION);
        }

        if (!$fileSuffix) return false;

        switch ($fileSuffix) {
            /*case 'jpeg':
                $theImage = @imagecreatefromjpeg($file);
                break;*/
            case '2':
                $theImage = imagecreatefromjpeg($file);
                break;
            case '3':
                $theImage = @imagecreatefrompng($file);
                break;
            case '1':
                $theImage = @imagecreatefromgif($file);
                break;
            default:
                $theImage = @imagecreatefromstring(file_get_contents($file));
                break;
        }

        return $theImage;
    }

    // 文字换行
    public function AutoWrap($fontsize, $angle, $fontface, $string, $width)
    {
        $content = "";
        for ($i = 0; $i < mb_strlen($string); $i++) {
            $letter[] = mb_substr($string, $i, 1);
        }

        foreach ($letter as $l) {
            $teststr = $content . "" . $l;
            $testbox = imagettfbbox($fontsize, $angle, $fontface, $teststr);
            if (($testbox[2] > $width) && ($content !== "")) {
                $content .= "\n";
            }
            $content .= $l;
        }
        $content = mb_convert_encoding($content, "html-entities", "utf-8");
        return $content;
    }

    public function getNetworkImgType($url)
    {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_NOBODY, 1);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 3);
        curl_setopt($ch, CURLOPT_TIMEOUT, 3);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_exec($ch);
        $http_code = curl_getinfo($ch);
        curl_close($ch);

        if ($http_code['http_code'] == 200) {
            $theImgType = explode('/', $http_code['content_type']);

            if ($theImgType[0] == 'image') {
                return $theImgType[1];
            } else {
                return false;
            }
        } else {
            return false;
        }
    }

    /**
     * 创建真彩画布
     * @param int $width
     * @param int $height
     * @param int $r
     * @param int $g
     * @param int $b
     * @return false|resource
     */
    public function createTrueColor(int $width, int $height, $r = 255, $g = 255, $b = 255)
    {
        $im = imagecreatetruecolor($width, $height);
        $color = imagecolorallocate($im, $r, $g, $b);
        imagefill($im, 0, 0, $color);
        return $im;
    }

    /**
     * 创建图像画布
     * @param $im
     * @param $imgUrl
     * @param $dst_w
     * @param $dst_h
     * @return bool|resource
     */
    public function createImgBoard($im, $imgUrl, $dst_x, $dst_y, $dst_w, $dst_h)
    {
        list($width, $height) = getimagesize($imgUrl);
        $imgBoard = Poster::createImageFromFile($imgUrl);
        imagecopyresized($im, $imgBoard, $dst_x, $dst_y, 0, 0, $dst_w, $dst_h, $width, $height);
        return $imgBoard;
    }

    /**
     * @param $im
     */
    public function lookImg($im)
    {
        header("Content-type:text/html;charset=utf-8");
        Header("Content-Type: image/jpeg"); // jpeg 生成会更快，png生成速度慢但是高清
        imagejpeg($im);
    }
}

使用方法

// 获取微信二维码
$codePath = Qrcode::createQrcode([
    'scene' => $scene,
    'page' => $path,
    'width' => '112',
    'auto_color' => false,
    'line_color' => [
        'r' => 0,
        'g' => 0,
        'b' => 0
    ]
]);
$data = [
    'bg' => $this->bg,
    'goodsPath' => $goodsPath,
    'title' => $goodsName,
    'price' => $goodsPrice,
    'btn' => $this->btn,
    'time' => date('Y-m-d H:i'),
    'qrcode' => $codePath,
    'headimg' => $userInfo->headimgurl ? $userInfo->headimgurl : $this->defaultHeadImg,
    'nickname' => $userInfo->nickname ? $userInfo->nickname : '特抱抱'
];
$this->createPoster($data);

效果图

 从上面两个图很明显可以看出，第二张图下面被切掉了，而且电脑是打不开的。解决这个问题的关键在于ob_clean();ob_end_clean();两个函数。

解决方法

// 清空缓冲区
ob_clean();
ob_end_clean();