PHP处理base64编码字符串

$photo = \Yii::$app->request->post('photo', '');    //yii接收,photo变量存储的即base64字符串  

$filename = date('YmdHis').rand(1111,9999).'.png';
$path = \Yii::$app->basePath.'/web/temp';  

if(!is_dir($path)){
    mkdir($path, 0777, 'true');
}  

$imagePath = $path.'/'.$filename;  //文件的完整路径(本地的)  

if(strstr($photo, ',')){
    $photo = explode(',', $photo);
    $photo = $photo[1];
}  

$r = file_put_contents($imagePath, base64_decode($photo));   //$r接收的是返回的字节数, 至此本地成功生成图片  

$photo_url = $this->uploadImg($imagePath);  //调用上传oss方法
//删掉本地图片
unlink($imagePath);  

public $access_key = '你的access_key';
public $secret_key = '你的secret_key';
public $domain = 'http://oss-cn-shenzhen.aliyuncs.com';  //选距离最近的域名
public $bucket = '你的bucket';
//$localdir是图片的本地路径, 也就是$imagePath
public function uploadImg($localdir='')
    {
        include \Yii::$app->basePath.'extensions/aliyun-oss-php-sdk-2.2.4/autoload.php';  //将ossSDK包放在extensions目录下, 然后引入autoload.php, 还有命名空间. 即可使用.
        //把文件上传到oss上
        try{
            $object = md5(time().uniqid()).'.png';
            $ossClient = new OssClient($this->access_key, $this->secret_key, $this->domain);
            $exist = $ossClient->doesObjectExist($this->bucket, $object);
            if(!$exist){
                $ossClient->uploadFile($this->bucket, $object, $localdir);
            }
           
            $domain = explode('//', $this->domain);
            $url = 'http://'.$this->bucket.'.'.$domain[1].'/'.$object; //拼接访问路径
//            $data = [
//                'status' => 0,
//                'msg' => 'success',
//                'url' => $url,
//            ];
            return $url;
        } catch(OssException $e) {
            printf(__FUNCTION__ . ": FAILED\n");
            printf($e->getMessage() . "\n");
            return;
        }
    }