Openlayers为线要素添加文字标注

似乎只能给点要素添加标注？？

1. 加载矢量点实现标注

2. 使用重叠层实现标注

参考：https://blog.csdn.net/qq_35732147/article/details/81771953（OpenLayers之标注功能二：图文标注）

为marker添加标注：https://q.cnblogs.com/q/27959/

openlayers给要素加文字注记：https://blog.csdn.net/u013594477/article/details/83584294

openlayers文字标注 (九)：https://blog.csdn.net/m0_37797410/article/details/106503770

怎么给线标注呢？

openlayers实现带箭头的线路polyline：https://zhuanlan.zhihu.com/p/336831271

How to add style in polyline in openLayers?：https://stackoverflow.com/questions/64143861/how-to-add-style-in-polyline-in-openlayers

How to add text to LineString in OpenLayers?

Setting OpenLayers line labels by angle?：https://gis.stackexchange.com/questions/333475/setting-openlayers-line-labels-by-angle

不知怎么滴，又可以了：

方法一：

text: new ol.style.Text({                         font: '13px Microsoft YaHei',                         text:  name,                         textAlign:"left",                         fill: new ol.style.Fill({                             color: '#666'                         }),                         stroke: new ol.style.Stroke({                           color: '#f2f',                           width: 1                         })              }) 方法二：               // text: new ol.style.Text({               //   text:'aaaaa',               //   font: '14px Verdana',               //   fill: new ol.style.Fill({               //     color: '#000000'               //   }),               //   stroke: new ol.style.Stroke({               //     color: '#f2f',               //     width: 1               //   })               // })