基于缩放级别显示功能

Question

我是 openlayers 库的新手，我有一个问题。我渲染了很多要素，当地图缩小时，要素相互重叠，看起来很丑陋，正如您在第一个屏幕截图中看到的那样。我希望缩小的地图（第一个屏幕）在所有缩放级别看起来都像放大的地图（第二个屏幕）。最常见的实施方式是什么？

Answer 1

下面是一个样式函数示例，它从聚类地图图层中检测组特征，并为单个对象绘制正方形，为组对象绘制圆圈：

var styleFunction = function() {
  return function(feature,resolution) {
    var style;
    var radius;
    var offsetY = -26;
    var gotGroup = false;

    var features = feature.get('features');

    if (features.length == 1) { //length = 1 - individual object instead of combo object
      style = new ol.style.Style({
        image: new ol.style.RegularShape({
        radius: 10,
        points: 4,
        angle: Math.PI / 4,
        fill: createFillStyle(feature),
        stroke: createStrokeStyle(feature,resolution,props)
        }),
        text: createTextStyle(feature, resolution, props)
      });
    } else {
      var rad = 11;
      if (features.length > 1) { //If group of features increase radius of object
        rad = 12;
        gotGroup = true;
      }
      style = new ol.style.Style({
        image: new ol.style.Circle({
        radius: rad,
        fill: createFillStyle(feature),
        stroke: createStrokeStyle(feature,resolution,props)
      }),
      text: createTextStyle(feature, resolution, props)
    });
  }
  return [style];
};
};

希望这对您的项目有所帮助

基于缩放级别显示功能

Displaying features based on zoom level

openlayers

openlayers-3