我开始在我的包的控制器的configure方法中创建一个新的缩略图类型,如下所示：

use Concrete\Core\File\Image\Thumbnail\Type\Type;

...

public function configure($pkg) {
    ...

    $thumbnailType = new Type();
    $thumbnailType->setName(tc('ThumbnailTypeName','PDF Thumbnails'));
    $thumbnailType->setHandle('pdfthumbnails');
    $thumbnailType->setWidth(200);
    $thumbnailType->setHeight(200);
    $thumbnailType->save();
}

然后我创建了一个类mypackage / src / document_PRocessing / pdfthumbnails.PHP,其中包含以下内容：

namespace Concrete\Package\Mypackage\Src\DocumentProcessing;

use Core;
use File;
use Concrete\Core\File\Image\Thumbnail\Type\Type;

class Pdfthumbnails {

    public function processPDFThumbnails($fv) {
        $fi = Core::make('helper/file');
        $fvObj = $fv->getFiLeversionObject();
        $ext = $fi->getExtension($fvObj->getFilename());
        $file = $fvObj->getFile();
        if ($ext == 'pdf') {
            $type = Type::getByHandle('pdfthumbnails');
            $basetype = $type->getBaseVersion();
            $thumbpath = $basetype->getFilePath($fvObj);

            $fsl = $file->getFileStorageLocationObject()->getFileSystemObject();
            $fre = $fvObj->getFileResource();
            // this requires sufficient permissions..
            // depending on your SETUP,reconsider 0777
            mkdir('application/files'.dirname($thumbpath),0777,true);
            exec('gs -o application/files'.escapeshellarg($thumbpath).' -dPDFFitPage -sDEVICE=png16m -g200x200 -dLastPage=1 -f application/files/'.escapeshellarg($fre->getPath()));
        }
    }
}

然后我迷上了我的包的控制器中的on_file_version_add事件：

use Concrete\Package\Mypackage\Src\DocumentProcessing\Pdfthumbnails;

...

    public function on_start() {
        Events::addListener('on_file_version_add',array(new Pdfthumbnails(),'processPDFThumbnails'));
    }