定义一个Block

假设你的模块名叫: nice_menus

你需要创建以下目录: nice_menus/src/Plugin/Block/  并且文件名要包含类名比如: NiceMenusBlock  (nice_menus/src/Plugin/Block/NiceMenusBlock.php)

定义BLock代码

/**
 * @file
 * Contains \Drupal\nice_menus\Plugin\Block\NiceMenusBlock.
 */
 
namespace Drupal\nice_menus\Plugin\Block;
 
use Drupal\block\BlockBase;
use Drupal\Component\Annotation\Plugin;
use Drupal\Core\Annotation\Translation;
 
// Drupal 8中的Block信息是以注释的方式来定义的, 以下这段注释里面就是定义此Block信息
 
/**
 * Provides a Nice menus block.
 *
 * @Block(
 *   id = "nice_menus_block",
 *   admin_label = @Translation("Nice menus"),
 *   module = "nice_menus"
 * )
 */
class NiceMenusBlock extends BlockBase {
}

ID属性是Block的机器名, 也是此BLock的唯一标示符,

设置表单配置

/**
 * @file
 * Contains \Drupal\nice_menus\Plugin\Block\NiceMenusBlock.
 */
 
namespace Drupal\nice_menus\Plugin\Block;
 
use Drupal\block\BlockBase;
use Drupal\Component\Annotation\Plugin;
use Drupal\Core\Annotation\Translation;
 
/**
 * Provides a Nice menus block.
 *
 * @Block(
 *   id = "nice_menus_block",
 *   admin_label = @Translation("Nice menus"),
 * )
 */
class NiceMenusBlock extends BlockBase {
 
  /**
   * 定义表单
   * Overrides \Drupal\block\BlockBase::blockForm().
   */
  public function blockForm($form, &$form_state) {
 
    // 读取配置.
    $configuration = $this->configuration;
    $form['testfield'] = array(
      '#type' => 'textfield',
      '#title' => t('Menu name'),
      '#default_value' => isset($configuration['testfield']) ? $configuration['testfield'] : '',
    );
    return $form;
  }
 
  /**
   * 保存表单配置的值
   * Overrides \Drupal\block\BlockBase::blockSubmit().
   */
  public function blockSubmit($form, &$form_state) {
    $this->setConfigurationValue('testfield', $form_state['values']['testfield']);
  }
}

BLOCK的输出

/**
 * @file
 * Contains \Drupal\nice_menus\Plugin\Block\NiceMenusBlock.
 */
 
namespace Drupal\nice_menus\Plugin\Block;
 
use Drupal\block\BlockBase;
use Drupal\Component\Annotation\Plugin;
use Drupal\Core\Annotation\Translation;
 
/**
 * Provides a Nice menus block.
 *
 * @Block(
 *   id = "nice_menus_block",
 *   admin_label = @Translation("Nice menus"),
 * )
 */
class NiceMenusBlock extends BlockBase {
 
  /**
   * 定义表单
   * Overrides \Drupal\block\BlockBase::blockForm().
   */
  public function blockForm($form, &$form_state) {
 
    // 读取配置.
    $configuration = $this->configuration;
    $form['testfield'] = array(
      '#type' => 'textfield',
      '#title' => t('Menu name'),
      '#default_value' => isset($configuration['testfield']) ? $configuration['testfield'] : '',
    );
    return $form;
  }
 
  /**
   * 保存表单配置的值
   * Overrides \Drupal\block\BlockBase::blockSubmit().
   */
  public function blockSubmit($form, &$form_state) {
    $this->setConfigurationValue('testfield', $form_state['values']['testfield']);
  }
 
   /**
   * BLock输出, 这里只输出配置的值
   * {@inheritdoc}
   */
  public function build() {
    return $this->configuration['testfield'];
  }
}