为何picker-view无法显示出来？

为何picker-view无法显示出来？

js:

export default {

    data: {

        picker1range: ["1","2","3"]

    }

}

hmt:

<div class="container">

    <text class="txt">分1</text>

    <picker-view class="pv1" range = '{{picker1range}}' />

     <text class="txt">分2</text>

    <picker-view class="pv1" range="{{picker1range}}" />

    <text class="txt">分3</text>

    <input type="button" value="点我" class="btn" on:click="clickAction" />

</div>

CSS:

.pv1{

    width: 200px;

    height: 250px;

}