我怎样才能在将图层添加到地图时将其添加为 OpenLayers 3 中的底层？

Question

我正在想办法切换地图类型并将图层添加为底层。其他层是应该始终位于顶部的信息层。我尝试使用 map.baseLayer 属性但该层仍呈现在其他层之上。

这是我得到的：

var OSMLayer = new ol.layer.Tile({
    source: new ol.source.OSM()
});

// Initial map
var currentMap = OSMLayer;

var mapQuestOSMLayer = new ol.layer.Tile({
    source: new ol.source.MapQuest({layer: 'osm'})
});

var mapQuestSATLayer = new ol.layer.Tile({
    source: new ol.source.MapQuest({layer: 'sat'})
});
var mapQuestHYBLayer = new ol.layer.Tile({
    source: new ol.source.MapQuest({layer: 'hyb'})
});

var map = new ol.Map({
  layers: [OSMLayer],
  target: document.getElementById('map-canvas'),
  view: new ol.View({
    center: [0, 0],
    zoom: 3
  })
});

// How can i set the layer as the bottom layer?

$('#btnMapTypes ul.dropdown-menu li a').click(function (e) {
    map.removeLayer(currentMap);
    switch($(this).attr('data-type')){
        case 'OSM':
            map.addLayer(OSMLayer);
            map.baseLayer = OSMLayer;
            currentMap = OSMLayer;
        break;
        case 'mapQuestOSM':
            map.addLayer(mapQuestOSMLayer);
            map.baseLayer = mapQuestOSMLayer;
            currentMap = mapQuestOSMLayer;
        break;
        case 'mapQuestSAT':
            map.addLayer(mapQuestSATLayer);
            map.baseLayer = mapQuestSATLayer;
            currentMap = mapQuestSATLayer;
        break;
        case 'mapQuestHYB':
            map.addLayer(mapQuestHYBLayer);
            map.baseLayer = mapQuestHYBLayer;
            currentMap = mapQuestHYBLayer;
        break;
    }           
});

实现我想要的结果的正确方法是什么？谢谢！

Answer 1

如果你在地图上执行 getLayers，你会得到一个集合，它具有操作顺序的功能，例如 insertAt（或 setAt 取决于你的需要）：http://openlayers.org/en/v3.8.2/apidoc/ol.Collection.html

我怎样才能在将图层添加到地图时将其添加为 OpenLayers 3 中的底层？

How can i make so that when a layer is added to a map it is added as the bottom layer in OpenLayers 3?

javascript

openlayers-3