movable-view设置为可缩放，当放大超过movable-area的宽度后，movable-view就不能进行缩放了

代码：

<movable-area style="height: 400px; width: 100%; background: red;" scale-area>

    <movable-view style="height: 200px; width: 100%; background: blue;" direction="all" bindchange="onChange" bindscale="onScale" scale scale-min="1" scale-max="2" scale-value="1">

        <image style="width: 100%; height: 200px;" src="https://mp.weixin.qq.com/debug/wxadoc/dev/image/cat/0.jpg?t=2018518" />

    </movable-view>

</movable-area>