https://developers.weixin.qq.com/miniprogram/dev/reference/wxml/

<view wx:if="{{view == 'WEBVIEW'}}"> WEBVIEW </view>
<view wx:elif="{{view == 'APP'}}"> APP </view>
<view wx:else="{{view == 'MINA'}}"> MINA </view>

第三行应为 wx:elif 或者去除条件