OpenLayers 修改要素样式而不覆盖交互样式

Question

有没有办法在不修改 select 交互默认样式的情况下修改单个功能的样式？

这是一段显示我的问题的简单代码和 jsfiddle

最小 html：

<input type="button" id="switcher" value="Change style"></input>
<div id="map" class="map"></div>

还有一个简单的脚本：

let vectorLayer = new ol.layer.Vector({
  source: new ol.source.Vector({wrapX: false})
});

let map = new ol.Map({
  target: 'map',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM({wrapX: false})
    }),
    vectorLayer,
  ],
  view: new ol.View({
    center: ol.proj.transform([9, 44.65], 'EPSG:4326', 'EPSG:3857'),
    zoom: 8
  })
});

let source = vectorLayer.getSource();

let draw = new ol.interaction.Draw({
  source: source,
  type: 'Polygon'
});

let selectOnHover = new ol.interaction.Select({
    source: source,
    condition: ol.events.condition.pointerMove
});

map.addInteraction(draw);
map.addInteraction(selectOnHover);

let fill = new ol.style.Fill({
  color: 'rgba(255,0,255,0.4)'
});
let stroke = new ol.style.Stroke({
  color: '#00FF00',
  width: 5
});
let customStyle = new ol.style.Style({
  image: new ol.style.Circle({
    fill: fill,
    stroke: stroke,
    radius: 5
  }),
  fill: fill,
  stroke: stroke
});

document.getElementById('switcher').onclick = function(event) {
  let features = source.getFeatures();
  if(features.length>0)
    features[0].setStyle(customStyle);
}

正如您在 jsfiddle 上的测试所见，单击按钮将正确更改第一个绘制要素的样式，但似乎也会覆盖悬停时的默认样式（这里只是 select 与条件的交互).

如何在更改功能样式时保持悬停时的默认样式？

Answer 1

功能上的样式会覆盖所有样式功能（以及交互的默认样式等）。但是你可以给一个特性一个 customStyle 属性并且只在图层样式函数中使用它而不是默认样式，而交互将继续使用默认的交互。

let defaultFill = new ol.style.Fill({
  color: 'rgba(255,255,255,0.4)'
});
var defaultStroke = new ol.style.Stroke({
  color: '#3399CC',
  width: 1.25
});
var defaultStyles = [
  new ol.style.Style({
    image: new ol.style.Circle({
      fill: defaultFill,
      stroke: defaultStroke,
      radius: 5
    }),
    fill: defaultFill,
    stroke: defaultStroke
  })
];

let vectorLayer = new ol.layer.Vector({
  source: new ol.source.Vector({wrapX: false}),
  style: function(feature) { 
    var customStyle = feature.get('customStyle');
    return customStyle || defaultStyles;
  }
});


...
...

document.getElementById('switcher').onclick = function(event) {
  let features = source.getFeatures();
  if(features.length>0)
    features[0].set('customStyle', customStyle);
}

OpenLayers 修改要素样式而不覆盖交互样式

OpenLayers modify feature style without overwritting interactions style

javascript

openlayers-5