select2在jqueryui dialog里没反应

在dialog前加入_allowInteraction的重载.
$.widget("ui.dialog", $.ui.dialog, {
    open: function () {
        return this._super();
    },
    _allowInteraction: function (event) {
        return !!$(event.target).is(".select2-search__field") || this._super(event);
    }
});

参考 http://www.cnblogs.com/liminjun88/p/3700087.html