ui-bootstrap modal无法打开

Question

我正在使用Bootstrap 4.0.0和ui-bootstrap4 ^ 3.0.6。当我激活打开模态的功能时，它只会显示叠加层，而不会透明且没有模态。可能会发生什么？

modal.html

<div class="modal" tabindex="-1" role="dialog">
    <div class="modal-dialog" role="document">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title">Modal title</h5>
                <button type="button" class="close"
                        data-dismiss="modal" aria-label="Close">
                  <span aria-hidden="true">&times;</span>
                </button>
            </div>
            <div class="modal-body">
                <p>Modal body text goes here.</p>
            </div>
            <div class="modal-footer">
                <button type="button" class="btn btn-primary">
                  Save changes
                </button>
                <button type="button" class="btn btn-secondary"
                        data-dismiss="modal">
                  Close
                </button>
            </div>
        </div>
    </div>
</div> 

controller.js

    //Modal
    $scope.openModal = function() {
        $uibModal.open({
            templateUrl: '../../../pages/component/modal.html',
            controller: function($scope, $uibModalInstance) {
                $scope.ok = function() {
                    $uibModalInstance.close();
                };
                $scope.cancel = function() {
                    $uibModalInstance.dismiss('cancel');
                };
            }
        })
    };

ui-bootstrap4