在Drupal8中以编程方式构建view-sum行

<?php

namespace Drupal\your_module\Plugin\views\field;

use Drupal\views\Plugin\views\field\FieldPluginBase;
use Drupal\views\ResultRow;

/**
 * Defines a custom sum field for views.
 *
 * @ViewsField("your_module_sum_field")
 */
class SumField extends FieldPluginBase {

  /**
   * {@inheritdoc}
   */
  public function query() {
    // 不需要进行查询操作，因为sum行只是显示字段的总和值
  }

  /**
   * {@inheritdoc}
   */
  public function render(ResultRow $values) {
    // 获取字段值的总和
    $sum = 0;
    foreach ($this->getEntityIds($values) as $id) {
      $entity = $this->getEntity($id);
      // 假设要计算的字段是'field_example'，可以根据实际情况修改
      $sum += $entity->get('field_example')->value;
    }

    return $sum;
  }

}

<?php

use Drupal\views\Entity\View;
use Drupal\views\Views;

/**
 * Implements hook_views_data_alter().
 */
function your_module_views_data_alter(array &$data) {
  $data['node_field_data']['your_module_sum_field'] = [
    'title' => t('Sum Field'),
    'help' => t('Displays the sum of a field.'),
    'field' => [
      'id' => 'your_module_sum_field',
    ],
  ];
}

/**
 * Implements hook_views_plugins().
 */
function your_module_views_plugins() {
  $plugins = [];

  // Register the custom field plugin.
  $plugins['field']['your_module_sum_field'] = [
    'title' => t('Sum Field'),
    'class' => '\Drupal\your_module\Plugin\views\field\SumField',
    'tag' => 'your_module_sum_field',
  ];

  return $plugins;
}