小程序提示报Now you can provide attr wx:key for a wx:for to improve performance.

如果小程序里面你发现自己哪里都没写错,却提示以下内容,

Now you can provide attr "wx:key" for a "wx:for" to improve performance.

解决方法:

在wx:for='{{}}'和 wo:for-item='' 中间加一个 wx:key="key"

<block wx:for='{{movies}}' wx:key="key" wo:for-item='movie'>