OpenLayers：将 map 锁定到向量的范围

Question

I'm learning how it is possible to create a library in JavaScript using OpenLayers. Normally I use the code below to lock my map on the vector extent passed manually.

var minX= 3.0025038498794938;
var minY= 47.7706339888675302;
var maxX= 5.1702255722362533;
var maxY= 49.5690401585264695;
var maxExtent = [minX, minY, maxX, maxY];
var boundary = ol.proj.transformExtent(maxExtent, 'EPSG:4326', 'EPSG:3857');
var center = ol.proj.transform([4.0863647111, 48.6698370737], 'EPSG:4326', 'EPSG:3857');

var view = new ol.View({
  extent: boundary,
  center: center,
  zoom: 9,
  maxZoom: 18,
  minZoom: 8,
});
map.setView(view);

My aim is use the same phylosophy but using the extent of a vector inside a specific function. I'm be able to load the map on a zoom on the vector extensions:

function getPolygonsExtent() {
  vectorsLayer.getSource().once('change', function(evt) {
    if (vectorsLayer.getSource().getState() === 'ready') {
      if (vectorsLayer.getSource().getFeatures().length > 0) {
        extent = vectorsLayer.getSource().getExtent();
        options = {
          size: map.getSize(),
          padding: [0, 0, 0, 0],
        }
        map.getView().fit(extent, options);
      }
    }
  });
};

But I've no idea how I can follow my aim. I thought there was a function like map.getView().setExtent(extent); , but is is not so. Any suggestions?

Answer 1

There is no setExtent() method so you will need to create a new view

  map.getView().fit(extent, options);
  var newView = new ol.View({
    extent: extent,
    showFullExtent: true,
    center: map.getView().getCenter(),
    zoom: map.getView().getZoom(),
    maxZoom: 18,
    minZoom: 8,
 });
 map.setView(newView);

The fit() method fits the extent inside the map, but by default the extent option constrains the map inside the extent, use showFullExtent for similar behaviour to fit() . If your fit options include a duration you will also need a callback to update the view when it is finished inside of doing it in inline code.