select2在模态框下无法得到焦点

在模态框加载时，添加重写enforceFocus方法:

 $.fn.modal.Constructor.prototype.enforceFocus = function() {};

我当时加在项目代码：

$('#myModal').modal({ backdrop: 'static', keyboard: false });
$.fn.modal.Constructor.prototype.enforceFocus = function () { };
$('#myModal').modal();