core/Form.php
public function getFirstError()
    {
        $fields = $this->getFields();
        foreach ($fields as $field) {
            if (!empty($field->error)) {
                return $field->error;
            }
        }
        return null;
    }
public function getFirstError()
    {
        $fields = $this->getFields();
        foreach ($fields as $field) {
            if (!empty($field->error)) {
                return $field->error;
            }
        }
        return null;
    }
获取第一条错误
@return null