正在加载源向量(功能不会显示?) [英] Loading source vector (Features won't show?)
问题描述
我有一个从本地geojson文件加载矢量源的函数.
I have a function that loads a vector source from a local geojson file.
问题是，我需要使它对于其中的一层是远程的，但是尽管正确加载了源并且console.logs确实显示了它们的确获取了它们，但是这些功能却从未显示过……如果我将发生奇怪的事情省略以下行:"this.layerSwitcherGroup.getLayers().push(this.pointsLayer);"从代码.注释该行后，加载程序将永远不会运行(内部不会显示console.logs).
Problem is, I need it to be remote for one of the layers, yet the features never show despite loading the source properly and the console.logs showing me it did indeed fetch them...plus a weird thing happens if I omit the line: "this.layerSwitcherGroup.getLayers().push(this.pointsLayer);" from the code. When that line is commented, the loader never runs (no console.logs appear from inside it).
注意:我只是临时编辑crs，直到服务器中的文件的crs更新为非旧文件为止.通过下载本地文件并编辑crs部分，使用本地功能从服务器测试geojson文件时，我执行了相同的操作.本地功能有效，但远程功能无效.
Note: I am editing the crs only temporarily until the file in the server has the crs updated to a non-legacy one. I did the same when I tested the geojson file from the server with local function by downloading it and editing the crs part. Local function worked, but remote doesn't.
addPoints: function() {
this.addPointInteraction();
this.pointsLayer = new ol.layer.Vector({
source: new ol.source.Vector({
/**
* The function is responsible for loading the features and adding them to the source.
* ol.source.Vector sources use a function of this type to load features.
* @param extent - the area to be loaded
* @param resolution - the resolution (map units per pixel)
* @param projection - ol.proj.Projection for the projection as arguments
*
* this (keyword): within the function is bound to the ol.source.Vector it's called from.
*/
loader: function(extent, resolution, projection) {
console.log('vector Loader...');
var url = //can't show the url here;
$.ajax({
url: url,
context: this,
success: function(json) {
console.log('Data: ', json);
json.data.crs = {
"type": "name",
"properties": {
"name": "urn:ogc:def:crs:OGC:1.3:CRS84"
}
};
console.log('changed CRS: ', json);
var features = new ol.format.GeoJSON().readFeatures(json.data);
console.log('this inside loader: ', this);
this.addFeatures(features);
}
});
}
}),
style: this.defaultPointStyleFunction
});
this.layerSwitcherGroup.getLayers().push(this.pointsLayer);
this.pointsLayer.getSource().once("change", function(evt) {
console.log('pointsLayer once');
//console.log('pointsLayer changed: ', this.pointsLayer);
//console.log('pointsLayer source: ', this.pointsLayer.getSource());
console.log('pointsLayer features: ', this.pointsLayer.getSource().getFeatures());
//console.log('current layerSwitcherGroup layers: ', this.layerSwitcherGroup.getLayers());
this.hidePoints();
this.onSetSelection(1);
}, this);
this.currPointId = null;
},
上面列出的每个函数都可以在本地模式下使用，所以我不太确定远程加载程序在做什么错...
Every function that is listed above works with local mode, so I'm not quite sure what am I doing wrong with the remote loader...
推荐答案
所以我所缺少的只是向readFeatures添加了{featureProjection:'EPSG:3857'}，以便可以正确地将特征投影到地图视图中... (因为这是地图投影)
So all I was missing was adding {featureProjection: 'EPSG:3857'} to readFeatures so that the features would be projected in the map view correctly... (since that is the map projection)
通过替换
var features = new ol.format.GeoJSON().readFeatures(json.data);
使用
var features = format.readFeatures(json.data, {featureProjection: 'EPSG:3857'});
通过找到了它，https://stackoverflow.com/a/32455939/2340999 中显示了这些功能现在合适的位置！
Found it through https://stackoverflow.com/a/32455939/2340999 and the features are showing in the proper positions now!
感谢您的所有建议！
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