[英]OpenLayers destroyFeatures() doesn't destroy features when using a clustering strategy
與OpenLayers中描述的問題類似:放大或縮小后,重新出現銷毀的功能
在向量層上調用destroyFeatures()或removeAllFeatures()(或兩者,以任何順序)。 功能從視圖中消失。 但是然后放大或縮小,它們會重新出現。 對我來說,只有在使用集群策略時才會發生這種情況。 似乎群集特征似乎已被破壞,但該群集所代表的基礎特征並未被破壞,因此,當放大或縮小時,將根據這些基礎特征重新計算並重新繪制群集。
Googling揭示了幾年前OpenLayers的開發人員之間的許多有關destroyFeatures()問題的對話。 令人驚訝的是,即使到現在,問題似乎仍未完全解決。
我可以通過破壞整個層(使用destroy())然后在需要時重新創建它來解決該問題。 就我而言,這是可以的,但我可以想象出可能不希望使用這種大手筆的情況。
響應對代碼示例的請求,這是正在工作的版本中代碼的縮寫版本(即,使用destroy())。 在非工作版本中,我改為調用destroyFeatures()(並且未將圖層設置為null)。 如上所述,這最初會刪除功能,但是如果我隨后使用this.map.zoomIn()進行放大或縮小,功能將重新出現。
注意1:通過JavaScript橋從Objective-C調用這些函數。 注意2:JavaScript是使用CoffeeScript生成的。
(function() {
var addSightingsLayer, displayFeaturesForSightingsWithGeoJSONData, geoJSONFormat, load, map, projectionSphericalMercator, projectionWGS84, removeSightingsLayer, sightingsLayer;
addSightingsLayer = function() {
var context, layerStyle, layerStyleSelected, style, styleMap, styleSelected, yerClusteringStrategy;
if (!(this.sightingsLayer === null)) return;
yerClusteringStrategy = new OpenLayers.Strategy.Cluster({
distance: 10,
threshold: 2
});
this.sightingsLayer = new OpenLayers.Layer.Vector('Sightings', {
strategies: [yerClusteringStrategy]
});
this.map.addLayer(this.sightingsLayer);
style = {
// Here I define a style
};
context = {
// Here I define a context, with several functions depending on whether there is a cluster or not, eg:
dependentLabel: function(feature) {
if (feature.cluster) {
return feature.attributes.count;
} else {
return feature.attributes.name;
}
}, ....
};
layerStyle = new OpenLayers.Style(style, {
context: context
});
styleSelected = {
//...
};
layerStyleSelected = new OpenLayers.Style(styleSelected, {
context: context
});
styleMap = new OpenLayers.StyleMap({
'default': layerStyle,
'select': layerStyleSelected
});
this.sightingsLayer.styleMap = styleMap;
};
removeSightingsLayer = function() {
if (this.sightingsLayer === null) return;
this.sightingsLayer.destroy();
return this.sightingsLayer = null;
};
displayFeaturesForSightingsWithGeoJSONData = function(geoJSONData) {
if (this.sightingsLayer === null) JFOLMap.addSightingsLayer();
return this.sightingsLayer.addFeatures(this.geoJSONFormat.read(geoJSONData));
};
load = function() {
var lat, lon, osmLayer, zoom;
lat = ...;
lon = ...;
zoom = ...;
this.map = new OpenLayers.Map('mapDiv', {
controls: ...,
eventListeners: ...
});
osmLayer = new OpenLayers.Layer.OSM();
this.map.addLayer(osmLayer);
return this.map.setCenter(new OpenLayers.LonLat(lon, lat).transformWGS84ToSphericalMercator(), zoom);
};
OpenLayers.LonLat.prototype.transformWGS84ToSphericalMercator = function() {
return this.transform(JFOLMap.projectionWGS84, JFOLMap.projectionSphericalMercator);
};
OpenLayers.LonLat.prototype.transformSphericalMercatorToWGS84 = function() {
return this.transform(JFOLMap.projectionSphericalMercator, JFOLMap.projectionWGS84);
};
map = null;
sightingsLayer = null;
sightingsPopoverControl = null;
projectionWGS84 = new OpenLayers.Projection('EPSG:4326');
projectionSphericalMercator = new OpenLayers.Projection('EPSG:900913');
geoJSONFormat = new OpenLayers.Format.GeoJSON({
'externalProjection': projectionWGS84,
'internalProjection': projectionSphericalMercator
});
this.JFOLMap = {
map: map,
sightingsLayer: sightingsLayer,
projectionSphericalMercator: projectionSphericalMercator,
projectionWGS84: projectionWGS84,
geoJSONFormat: geoJSONFormat,
load: load,
addSightingsLayer: addSightingsLayer,
removeSightingsLayer: removeSightingsLayer,
displayFeaturesForSightingsWithGeoJSONData: displayFeaturesForSightingsWithGeoJSONData,
};
}).call(this);
試試這個,對我有用
layer.removeAllFeatures();
layer.destroyFeatures();//optional
layer.addFeatures([]);
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