javascript - 未捕获的 TypeError : . 可拖动不是函数(...)

Question

我不知道这里出了什么问题，它已经把我逼疯了。每当我在代码上使用一些断点时，如图所示，并重新加载页面，然后一切正常。但是如果我关闭开发人员工具然后刷新，它会抛出这个错误:'Uncaught TypeError: $design[a].draggable is not a function(...)'。

以下是我的代码和图片:

调试图片:

我的脚本:

    var canvas = document.getElementById("canvas");
    var ctx = canvas.getContext("2d");
    var $canvas = $("#canvas");
    var canvasOffset = $canvas.offset();
    var offsetX = canvasOffset.left;
    var offsetY = canvasOffset.top;

    var design = [];
    var $design = [];
    var pic = [];

    $.ajax({
      type: 'get',
      url: ('/getCustomizeParts'),
      data: {
      },
      success: function(data) {
        for (var a = 0; a < data.length; a++) {
          design[a] = new Image();
          pic[a] = data[a].partimagePath;
          design[a].src = "images/part/" + pic[a];
          $design[a] = $("#design" + (a + 1));
          //here it threows me the error
          $design[a].draggable({
            helper: 'clone',
          });
          $design[a].data("image", design[a]);
        }
        $canvas.droppable({
          drop: dragDrop,
        });
      }
    });

我已按以下顺序在我的页面中包含脚本标签

<script src="/Admin/js/jquery-2.2.3.min.js"></script>
<script src="/Admin/js/jquery-ui.min.js"></script>
<script src="/Admin/js/customizeScript.js"></script>

Answer 1

尝试将 defer 属性添加到您的脚本链接，如下所示:

<script src="/Admin/js/customizeScript.js" defer></script>
// or this for XHTML
<script src="/Admin/js/customizeScript.js" defer="defer"></script>

参见 this w3school page有关 defer 属性的更多信息