<xr-node wx:for="{{markerImg}}" wx:key="item.id">   

        <xr-ar-tracker id="ar-tracker" mode="Marker" src="{{item.src}}" bind:ar-tracker-state="handleARTrackerState">

        </xr-ar-tracker>

      </xr-node> 这种识别不了

将markerImg数组下的src提取单个变量，分别以markerImgitem0 ~ markerImgitem4，用以下方法可以识别，不知道什么原因

 <xr-ar-tracker id="ar-tracker" mode="Marker" src="{{markerImgitem0}}" bind:ar-tracker-state="handleARTrackerState">

      </xr-ar-tracker>  

      <xr-ar-tracker id="ar-tracker" mode="Marker" src="{{markerImgitem1}}" bind:ar-tracker-state="handleARTrackerState">

      </xr-ar-tracker> 

      <xr-ar-tracker id="ar-tracker" mode="Marker" src="{{markerImgitem2}}" bind:ar-tracker-state="handleARTrackerState">

      </xr-ar-tracker> 

      <xr-ar-tracker id="ar-tracker" mode="Marker" src="{{markerImgitem3}}" bind:ar-tracker-state="handleARTrackerState">

      </xr-ar-tracker>