php----图片上传封装类：单张，多张图片上传，生成缩略图

<?php
/**
 * 功能： 单张，多张图片上传，生成缩略图
 * Class ImgUpload
 */
class ImgUpload
{
    private $file;                  //文件信息
    private $fileList;            //文件列表
    private $inputName;     //标签名称
    private $uploadPath;    //上传路径
    private $fileMaxSize;    //最大尺寸
    private $uploadFiles;   //上传文件

    //允许上传的文件类型
    private $allowExt = array("bmp", "jpg", "jpeg", "png", "gif");

    /**
     * @param $inputName input标签的name属性
     * @param $uploadPath 文件上传路径
     */
    public function __construct($inputName, $uploadPath)
    {
        $this->inputName = $inputName;
        $this->uploadPath = $uploadPath;
        $this->fileList = array();
        $this->file = $file = array(
            "name" => null,
            "type" => null,
            "tmp_name" => null,
            "size" => null,
            "errno" => null,
            "error" => null
        );
    }

    /**
     * 设置允许上传的图片后缀格式
     * @param $allowExt 文件后缀数组
     */
    public function setAllowExt($allowExt)
    {
        if (is_array($allowExt)) {
            $this->allowExt = $allowExt;
        } else {
            $this->allowExt = array($allowExt);
        }
    }

    /**
     * 设置允许上传的图片规格
     * @param $fileMaxSize 最大文件尺寸
     */
    public function setMaxSize($fileMaxSize)
    {
        $this->fileMaxSize = $fileMaxSize;
    }

    /**
     * 获取上传成功的文件数组
     * @return mixed
     */
    public function getUploadFiles()
    {
        return $this->uploadFiles;
    }

    /**
     * 得到文件上传的错误信息
     * @return array|mixed
     */
    public function getErrorMsg()
    {
        if (count($this->fileList) == 0) {
            return $this->file["error"];
        } else {
            $errArr = array();
            foreach ($this->fileList as $item) {
                array_push($errArr, $item["error"]);
            }
            return $errArr;
        }
    }

    /**
     * 初始化文件参数
     * @param $isList
     */
    private function initFile($isList)
    {
        if ($isList) {
            foreach ($_FILES[$this->inputName] as $key => $item) {
                for ($i = 0; $i
< count($item); $i++) {
                    if ($key == "error") {
                        $this->
    fileList[$i]["error"] = null;
                        $this->fileList[$i]["errno"] = $item[$i];
                    } else {
                        $this->fileList[$i][$key] = $item[$i];
                    }
                }
            }
        } else {
            $this->file["name"] = $_FILES[$this->inputName]["name"];
            $this->file["type"] = $_FILES[$this->inputName]["type"];
            $this->file["tmp_name"] = $_FILES[$this->inputName]["tmp_name"];
            $this->file["size"] = $_FILES[$this->inputName]["size"];
            $this->file["errno"] = $_FILES[$this->inputName]["error"];
        }
    }

    /**
     * 上传错误检查
     * @param $errno
     * @return null|string
     */
    private function errorCheck($errno)
    {
        switch ($errno) {
            case UPLOAD_ERR_OK:
                return null;
            case UPLOAD_ERR_INI_SIZE:
                return "文件尺寸超过服务器限制";
            case UPLOAD_ERR_FORM_SIZE:
                return "文件尺寸超过表单限制";
            case UPLOAD_ERR_PARTIAL:
                return "只有部分文件被上传";
            case UPLOAD_ERR_NO_FILE:
                return "没有文件被上传";
            case UPLOAD_ERR_NO_TMP_DIR:
                return "找不到临时文件夹";
            case UPLOAD_ERR_CANT_WRITE:
                return "文件写入失败";
            case UPLOAD_ERR_EXTENSION:
                return "上传被扩展程序中断";
        }
    }

    /**
     * 上传文件校验
     * @param $file
     * @throws Exception
     */
    private function fileCheck($file)
    {
        //图片上传过程是否顺利
        if ($file["errno"] != 0) {
            $error = $this->errorCheck($file["errno"]);
            throw new Exception($error);
        }
        //图片尺寸是否符合要求
        if (!empty($this->fileMaxSize) && $file["size"] > $this->fileMaxSize) {
            throw new Exception("文件尺寸超过" . ($this->fileMaxSize / 1024) . "KB");
        }
        //图片类型是否符合要求
        $ext = pathinfo($file["name"], PATHINFO_EXTENSION);
        if (!in_array($ext, $this->allowExt)) {
            throw new Exception("不符合要求的文件类型");
        }
        //图片上传方式是否为HTTP
        if (!is_uploaded_file($file["tmp_name"])) {
            throw new Exception("文件不是通过HTTP方式上传的");
        }
        //图片是否可以读取
        if (!getimagesize($file["tmp_name"])) {
            throw new Exception("图片文件损坏");
        }
        //检查上传路径是否存在
        if (!file_exists($this->uploadPath)) {
            mkdir($this->uploadPath, null, true);
        }
    }

    /**
     * 单文件上传，成功返回true
     * @return bool
     */
    public function acceptSingleFile()
    {
        $this->initFile(false);
        try {
            $this->fileCheck($this->file);
           // $md_name = md5(uniqid(microtime(true), true)) . "." . pathinfo($this->file["name"], PATHINFO_EXTENSION);

           // 简单设置图片名
            $md_name = uniqid() . "." . pathinfo($this->file["name"], PATHINFO_EXTENSION);

            if (move_uploaded_file($this->file["tmp_name"], $this->uploadPath . $md_name)) {
                $this->uploadFiles = array($this->uploadPath . $md_name);
            } else {
                throw new Exception("文件上传失败");
            }
        } catch (Exception $e) {
            $this->file["error"] = $e->getMessage();
        } finally {
            if (file_exists($this->file["tmp_name"])) {
                unlink($this->file["tmp_name"]);
            }
        }
        return empty($this->file["error"]) ? true : false;
    }

    /**
     * 多文件上传，全部成功返回true
     * @return bool
     */
    public function acceptMultiFile()
    {
        $this->initFile(true);
        $this->uploadFiles = array();
        for ($i = 0; $i
    < count($this->
        fileList); $i++) {
            try {
                $this->fileCheck($this->fileList[$i]);
                $ext = pathinfo($this->fileList[$i]["name"], PATHINFO_EXTENSION);
                // $md_name = md5(uniqid(microtime(true), true)) . "." . $ext;

                // 简单设置图片名
                $md_name = uniqid() . "." . $ext;

                if (move_uploaded_file($this->fileList[$i]["tmp_name"], $this->uploadPath . $md_name)) {
                    array_push($this->uploadFiles, $this->uploadPath . $md_name);
                } else {
                    throw new Exception("文件上传失败");
                }
            } catch (Exception $e) {
                $this->fileList[$i]["error"] = $e->getMessage();
            } finally {
                if (file_exists($this->fileList[$i]["tmp_name"])) {
                    unlink($this->fileList[$i]["tmp_name"]);
                }
            }
        }
        foreach ($this->fileList as $item) {
            if (!empty($item["error"])) {
                return false;
            }
        }
        return true;
    }



     /**
     * 生成缩略图：
     * @param $picName 图片名. 为上传后图片的完整路径. 获取： $imgUpload->getUploadFiles()[0]
     * @param $max_w 缩略图宽度
     * @param $max_h 缩略图高度
     * @param $pre   缩缩略图前缀
     * @return bool
     */
    public function imgUpdateSize($picName, $max_w=100, $max_h=100, $pre="_s"){
        #1 获取图片的基本信息
        $info = getimagesize($picName);
        $w = $info[0];
        $h = $info[1];

        #2 获取图片的类型
        switch ($info[2]){
            case 1:         #gif
                $im = imagecreatefromgif($picName);
                break;
            case 2:         #jpeg
                $im = imagecreatefromjpeg($picName);
                break;
            case 3:         #png
                $im = imagecreatefrompng($picName);
                break;
            default :
                die("image style error!");
        }

        #3 计算缩放比例
        if(($max_w/$w) > ($max_h/$h)){
            $b = $max_h/$h;
        }else{
            $b = $max_w/$w;
        }

        #4 计算缩放后的尺寸
        $nw = floor($w*$b);
        $nh = floor($h*$b);

        #5 创建一个新的图像源 -目标画布
        $nim = imagecreatetruecolor($nw, $nh);

        # 等比例缩放
        imagecopyresampled($nim, $im, 0, 0, 0, 0, $nw, $nh, $w, $h);

        #6 输出图片 -按源图像的类型输出
        $picInfo = pathinfo($picName);        #解析源图像的名子与路径信息

        $new_picName = $picInfo["dirname"]."/".$picInfo["filename"] .$pre.".".$picInfo["extension"];    #拼装新图像名

        switch ($info[2]){
            case 1:         #gif
                imagejpeg($nim, $new_picName);
                break;
            case 2:         #jpeg
                imagejpeg($nim, $new_picName);
                break;
            case 3:         #png
                imagepng($nim, $new_picName);
                break;
            default :
                die("image style error!");
        }

        #7 释放图片资源
        imagedestroy($im);
        imagedestroy($nim);

        return $new_picName;
    }
}

测试github