Question

是否有任何方法可以修改单个功能的样式而无需在选择交互时修改默认样式？

这是显示我的问题的简单代码和a link

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);
}

正如通过在jsfiddle上进行测试所看到的那样，单击按钮将正确更改第一个绘制功能的样式，但似乎也将覆盖悬停时的默认样式（这里只是与条件的选择交互）。

更改特征样式时如何在悬停时保持默认样式？

Answer 1

要素上的样式会覆盖所有样式功能（以及交互的默认样式等）。但是您可以为一个功能提供customStyle属性，并仅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值进行交互。

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修改要素样式而不会覆盖交互样式

1 个答案: