|string> */ public function rules(): array { return [ 'file' => [ 'required', 'max:52428800', ], 'fileName' => [ 'nullable', 'max:150', function ($attribute, $value, $fail) { // 检查文件是否存在默认存储对象系统中 if (Storage::exists('uploads/' .date('Ymd/'). $value)) { $fail('File already exists'); } }, ] ]; } }