找不到Laravel 5.7“应用\导出\日期”类（Maatwebsite）

Question

我实现了maatwebiste（向excel导出）并试图对其进行改进。我只想在Excel中显示日期，而不以年/月/日的格式显示hh：mm：ss

所以我尝试了这种映射，但是遇到错误“找不到类'App \ Exports \ Date'”，但是我已经导入了WithMapping类。

任何提示为什么我会收到此错误？

PostExport

use App\Post;
use Illuminate\Contracts\Support\Responsable;
use Maatwebsite\Excel\Concerns\WithMapping;
use Maatwebsite\Excel\Concerns\WithHeadings;
use Maatwebsite\Excel\Concerns\FromQuery;
// use Maatwebsite\Excel\Concerns\FromCollection;
use Maatwebsite\Excel\Concerns\Exportable;

class PostExport implements FromQuery, Responsable, WithMapping, WithHeadings
{



public function map($post): array
    {
        return [
            Date::dateTimeToExcel($post->created_at),
        ];
    }

    public function query()
    {

        return Post::select('title','message','created_at','updated_at')
                            ->whereMonth('created_at',$this->to_month)
                            ->whereDay('created_at',$this->to_day)
                            ->whereyear('created_at',$this->to_year);
            // return Post::query()->whereMonth('created_at',$this->to_month)
            //                     ->whereDay('created_at',$this->to_day)
            //                     ->whereyear('created_at',$this->to_year);
    }