求那位大神看一下 拖拽报错

HTML5 使用拖拽时总是报错 Cannon read property 'setData' of undefined

$(".Jdata-add").on("dragstart","li",function(e){
e.dataTransfer.setData("Text",$(this).attr("class").slice(0, -4));
$(this).css("background","#333").css("color","#fff");
});

https://zhidao.baidu.com/question/1431490709433108539.html