how could i get all user role list in edit page in my custom module in magento 2

Question

I want to show user role list in my custom module edit page my code is as below

$fieldset->addField(
       'admin_role_ids',
       'multiselect',
       [
         'name'     => 'permission[admin_role_ids]',
         'label'    => __('Allowed for Roles'),
         'title'    => __('Allowed for Roles'),
         'values'   => $this->_adminSession->getUser()->getRole(),
       ]
    );

Answer 1

1) You can use class \Magento\Authorization\Model\ResourceModel\Role\Grid\Collection to get admin roles:

protected $roleCollectionFactory;

public function __construct(
  \Magento\Authorization\Model\ResourceModel\Role\Grid\CollectionFactory $roleCollectionFactory,
) {
  $this->roleCollectionFactory = $roleCollectionFactory;
}

public function getRoles()
{
    $role = $this->roleCollectionFactory->create();
    print_r($role->getData());
}

2) Use class Magento\Authorization\Model\ResourceModel\Role\Collection to get admin role with all admin user:

protected $roleCollectionFactory;

public function __construct(
  \Magento\Authorization\Model\ResourceModel\Role\CollectionFactory $roleCollectionFactory,
) {
  $this->roleCollectionFactory = $roleCollectionFactory;
}

public function getRoles()
{
    $role = $this->roleCollectionFactory->create();
    print_r($role->getData());
}