在index.html页面 head中加上：

<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover">
<meta name="viewport" content="width=device-width,initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"/>

即可解决拖动的问题