Method setVisibleScales

src/openlayers/mapping/WebMap.js:3325–3331

* @private * @function WebMap.prototype.setVisibleScales * @description 改变图层可视范围 * @param {Object} layer - 图层对象。ol.Layer * @param {Object} visibleScale - 图层样式参数

(layer, visibleScale)

   * @param {Object} visibleScale - 图层样式参数
   */
  setVisibleScales(layer, visibleScale) {
    let maxResolution = this.resolutions[visibleScale.minScale],
      minResolution = this.resolutions[visibleScale.maxScale];
    //比例尺和分别率是反比的关系
    maxResolution > 1 ? layer.setMaxResolution(Math.ceil(maxResolution)) : layer.setMaxResolution(maxResolution * 1.1);
    layer.setMinResolution(minResolution);
  }

  /**
   * @private