JQuery和select2选择器引用

Question

假设我有一个对象，其设置具有对元素的id引用，如下所示：

(function (Erasmus, $, undefined) {
    var settings = {
        Agreement : {
            SourceUniversity: "#scrUni",
        }
    };
    Erasmus.Settings = settings;
})(window.Erasmus = window.Erasmus || {}, jQuery);

现在所有选择输入都是select2，在初始化完所有内容之后，我将输入的更改事件绑定到这样：

(function (Erasmus, $, undefined) {
    var student = {
        BindPageControls: function () {
            $(Erasmus.Settings.Agreement.SourceUniversity).on("select2:select", function (selected) {
               console.log(selected); 
        });
      }
    };
    Erasmus.Student = student;
})(window.Erasmus = window.Erasmus || {}, jQuery);

现在的问题是，如果我绑定：

$(Erasmus.Settings.Agreement.SourceUniversity).on(...

它绑定到一个不同的对象（原始输入？）而不是select2输入并且不会触发事件，但如果我像这样绑定：

$("#srcUni").on(...

它工作得很好。为什么在将纯字符串和字符串作为变量传递时，JQuery会获取不同的引用？

JQuery版本3.2.1，select2版本4.0.4

Answer 1

以下是您的代码中的一个工作示例：

$(document).ready(function() {
  $('#srcUni').select2({
      placeholder: 'Select an option',
      width: 'resolve',
    	dropdownAutoWidth: 'true',
    	allowClear: 'true',
  });

  Erasmus.Student.BindPageControls();
});

(function (Erasmus, $, undefined) {
    var settings = {
        Agreement : {
            SourceUniversity: "#srcUni",
        }
    };
    Erasmus.Settings = settings;
})(window.Erasmus = window.Erasmus || {}, jQuery);

(function (Erasmus, $, undefined) {
    var student = {
        BindPageControls: function () {
            $(Erasmus.Settings.Agreement.SourceUniversity).on("select2:select", function (e) {
            var data = e.params.data;
            console.log("select item: ",data); 
        });
      }
    };
    Erasmus.Student = student;
})(window.Erasmus = window.Erasmus || {}, jQuery);

select {
  width: 200px
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.5/css/select2.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.5/js/select2.full.min.js"></script>

<select id="srcUni">
  <option value="1">Option 1</option>
  <option value="2">Option 2</option>
  <option value="3">Option 3</option>
</select>