IE11下，CKEditor在Bootstrap Modal中的下拉问题

$.fn.modal.Constructor.prototype.enforceFocus = function() {
    modal_this = this
    $(document).on(‘focusin.modal‘, function (e) {
        if (modal_this.$element[0] !== e.target && !modal_this.$element.has(e.target).length
            // Fix for CKEditor + Bootstrap IE issue with dropdowns on the toolbar
            // Adding additional condition ‘$(e.target.parentNode).hasClass(‘cke_contents cke_reset‘)‘ to avoid setting focus back on the modal window.
            && $(e.target.parentNode).hasClass(‘cke_contents cke_reset‘)) {
                modal_this.$element.focus()
        }
    })
};

Modal.prototype.enforceFocus = function () {
    $(document)
      .off(‘focusin.bs.modal‘) // guard against infinite focus loop
      .on(‘focusin.bs.modal‘, $.proxy(function (e) {
        if (document !== e.target &&
            this.$element[0] !== e.target &&
            !this.$element.has(e.target).length) {
          this.$element.trigger(‘focus‘)
        }
      }, this))
  }