css组件使用问题？

<view class=‘pn’>导演: <block wx:for=“{{item.directors}}” wx:for-item=“director” wx:for-index=“index”>

<view wx:if=“{{index==item.directors.length-1}}”>{{director.name}}</view>

<view wx:else=“{{index!=item.directors.length-1}}”>{{director.name}},</view>

</block>

麻烦哪位大佬解决一下