### Version 5.0.2 ### Reproduction link [https://codepen.io/tamersalama/pen/mdOraGb?editors=1111](https://codepen.io/tamersalama/pen/mdOraGb?editors=1111) ### Steps to reproduce 1- Create a *line* chart with a horizontal selector (lineX) brush 2- Use the brush to select a data range 3- The onbrushselected event fires up normally, however the event parameters' dataIndex (`params.batch[0].selected[0].dataIndex`) returns an empty array 4- Changing the chart type to scatter or bar will result in a proper dataIndex being returned ### What is expected? It's expected that the `dataIndex` for the selection to have an array of selected values ### What is actually happening? dataIndex within `params.batch[0].selected[0].dataIndex` is empty <!-- This issue is generated by echarts-issue-helper. DO NOT REMOVE --> <!-- This issue is in English. DO NOT REMOVE -->