使用@romanPErekhrest回答略有修改,我有我需要的东西.这会添加多个目录以递归搜索,同时过滤掉某些文件夹(在我的情况下：“_ _thumbs”文件夹).最终代码如下：

$dir1 = new Recursivedirectoryiterator("./folder01");
$dir2 = new RecursiveDirectoryITerator("./folder02");
$dir3 = new RecursiveDirectoryIterator("./folder03");
$iterators = new AppendIterator();

$filter = function ($file,$key,$iterator) {
    if ($iterator->hasChildren() && $file->getFilename() != "_thumbs") {
        return true;
    }
return $file->isFile();
};

$iterators->append(new RecursiveiteratorIterator( $dir1 ));
$iterators->append( $dir2 );
$iterators->append(new RecursiveIteratorIterator(new RecursiveCallbackFilterIterator($dir3,$filter)));

$rgIt = new RegexIterator($iterators,"/^.+\.jpg$/i");
$files = iterator_to_array($rgIt);

::原始问题::

我很难搞清楚RegexIterator.我正在尝试过滤掉RecursiveIteratorIterator扫描的父目录中的目录.在我的下面的代码中,$dir3有多个目录,因此RecursiveIteratorIterator,但它也有一个“_thumbs”目录,我不希望它处理. RegexIterator目前正在过滤并保留.jpg图像,但我还要杀死从“_thumbs”目录中获取的任何内容.

$dir1 = new RecursiveDirectoryIterator("./folder01");
$dir2 = new RecursiveDirectoryIterator("./folder02");
$dir3 = new RecursiveDirectoryIterator("./folder03"); // <<< this dir has a _thumbs directory that I don't want to PRocess
$iterators = new AppendIterator();

$iterators->append(new RecursiveIteratorIterator( $dir1 ));
$iterators->append( $dir2 );
$iterators->append(new RecursiveIteratorIterator( $dir3 ));

$rgIt = new RegexIterator($iterators,"/^.+\.jpg$/i");  //<<< this filters and keeps .jpg images.  I don't fully understand the Syntax though
$files = iterator_to_array($rgIt);


usort($files,function($a,$b){
    if(filectime($a) == filectime($b)){
        return 0;
    }
    return filectime($a) > filectime($b) ? -1 : 1;
});

$files = array_slice($files,18);

:: EDIT01 ::

这是我试过的另一个测试,但也没有随处可见.尝试使用RecursiveFilterIterator,但我怀疑我是否正确使用它.我得到的错误说“传递给RecursiveFilterIterator :: __ construct()的参数1必须实现接口RecursiveIterator,给出的AppendIterator实例”.

$dir1 = new RecursiveDirectoryIterator("./folder01");
$dir2 = new RecursiveDirectoryIterator("./folder02");
$dir3 = new RecursiveDirectoryIterator("./folder03");
$iterators = new AppendIterator();

$iterators->append(new RecursiveIteratorIterator( $dir1 ));
$iterators->append( $dir2 );
$iterators->append(new RecursiveIteratorIterator( $dir3 ));

class DirFilter extends RecursiveFilterIterator{
    public function accept(){
        $excludes = "/_thumbs";
        return !(in_array($this->getFilename(),$excludes));
    }
}

$filterItr = new DirFilter($iterators);

$rgIt = new RegexIterator($filterItr,"/^.+\.jpg$/i");
$files = iterator_to_array($rgIt);