Why does thinkphp5 always report errors when uploading multiple files using the multiple attribute?

error message:

HTML Code:

<input name="file" type="file" multiple/> 
<input type="submit" value="" class="btn btn-primary">

php Code:

if($files = request()->file("file"))          
            foreach ($files as $file) 
            {         
            $info = $file->move(ROOT_PATH . "public" . DS ."static","");
            if($info){
                $path_parts = pathinfo(ROOT_PATH . "public" . DS . "static" ."\\". $info->getFilename());
                //
                $type=$path_parts["extension"];
                $name=$path_parts["filename"];
                $size=(filesize(ROOT_PATH . "public" . DS . "static" ."\\". $info->getFilename())>>10)."KB";
                $data=["name"=>$name,"type"=>$type,"size"=>$size];
                Db::table("doc")->insert($data);

                $this->success("");
            }else{
                //
                $this->error($file->getError());    
            }
            } 

I am looking at the thinkphp5 manual, why does the move function always report an error?