OpenLayers 4-适合所选功能 [英] OpenLayers 4 - fit to extent of selected features

问题描述

又是我.因此，昨天我在缩放到选定的功能时遇到了一个问题，我希望你们中的一些人可以将我推向正确的方向.在这里...

Me again. So, yesterday I faced a bit of a problem with zooming to selected features and I'm hoping that some of you can push me in right direction.Here it goes...

我正在尝试使用Materialize Materialize Framework 来实现自动完成/搜索栏. (以下是简单搜索栏的示例)

I'm trying to implement autocomplete/search bar using Materialize Materialize Framework. (Here is fiddle example of simple searchbar)

  $(document).ready(function(){
    $('input.autocomplete').autocomplete({
      data: {
        "Apple": null,
        "Microsoft": null,
        "Google": 'https://placehold.it/250x250'
      },
    });
  });

现在，我想做的是使用geojson功能调用和填充数据，并实现针对所选功能的范围拟合.如果我理解正确，则需要保存所选功能的范围并用

Now, what I'm trying to do is to call and populate data using geojson features and to implement fit to extent for selected feature. If I'm understanding correctly I need to save extent for selected feature and pass it in with

map.getView().fit(selectedFeature.getSource().getExtent(), animationOptions);

还是我做这件事完全错误?

Or Am I doing this completely wrong?

$(document).ready(function() {
function sendItem(val) {
    console.log(val);
}

var animationOptions = {
    duration: 2000,
    easing: ol.easing.easeOut
};

$(function() {
    $.ajax({
        type: 'GET',
        url: 'geojson/jls.geojson',
        dataType: 'json',
        success: function(response) {
            var jls_array = response;
            var features = jls_array.features;
            var jls = {};

            for (var i = 0; i < features.length; i++) {
                var geo = features[i].properties;
                jls[geo['JLS_IME']] = null;
            }
            console.log(jls)
            $('input.autocomplete').autocomplete({
                data: jls,
                limit: 5,
                onAutocomplete: function(txt) {
                    sendItem(txt);
                    map.getView().fit(vectorJLS.getSource().getExtent(), animationOptions);
                }
            });
        }
    });
});
});

这是我的geojson对象的示例

And here is example of my geojson object

{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name":"EPSG:3765" } },
"features": [
{ "type": "Feature", "properties": { "JLS_MB": "00116", "JLS_IME": "BEDEKOVČINA", "JLS_ST": "OP", "JLS_SJ": "Bedekovčina", "ZU_RB": "02", "ZU_IME": "Krapinsko-zagorska", "ZU_SJ": "Krapina", "pov": 51.42 }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 461117.98, 5108379.85 ], [ 461124.53, 5108368.39 ], [ 461132.37, 5108354.26 ]...

更新-解决方案

因此，正如 Dube 同事用逻辑和实际的解决方案很好地指出的那样，他可以使用简单的.find()方法在geojson层源中查找特征并缩放选定的特征.

So, as fellow Dube nicely pointed out with logical and practical solution where he's finding feature and zooming selected feature within geojson layer source with simple .find() method.

在ajax调用之前，我只调整了一些带有添加变量的现有代码

I only tweaked a bit existing code with added variable before ajax call

var source_layer = vectorJLS.getSource(); // collecting layer source

$(function() {
    $.ajax({
        type: 'GET',
        url: 'geojson/jls.geojson',
        dataType: 'json'.....

onAutocomplete: function(txt) {
  var feature = source_layer.getFeatures().find(function(f) { return f.get('JLS_IME') === txt; });
  if (feature) {
    const extent = feature.getGeometry().getExtent()
    map.getView().fit(extent);
  }
};

这是我要迭代的图层，并选择放大功能

Here is layer that I'm trying to iterate and on select to zoom on feature

推荐答案

要素本身不具有范围，但是其几何图形具有一个范围:

The feature itself does not have an extent, but it's geometry has one:

const extent = feature.getGeometry().getExtent()
map.getView().fit(extent);

但是，到目前为止，您似乎还没有在ajax响应中获得的OpenLayers功能对象，只是一个普通的json对象.让我们对其进行转换:

However, so far you seem not to have OpenLayers feature objects, just a plain json object, which you got in the ajax response. Let's transform it:

var source = new ol.source.Vector({
features: (new ol.format.GeoJSON({
  featureProjection: "EPSG:3765" // probably not required in your case
})).readFeatures(featureCollection);

您无需将矢量添加到地图即可确定特定特征及其范围:

You do not need to add the vector to the map to determine the specific feature and it's extent:

onAutocomplete: function(txt) {
  var feature = source.getFeatures().find(function(f) { return f.get('JLS_IME') === txt; });
  if (feature) {
    const extent = feature.getGeometry().getExtent()
    map.getView().fit(extent);
  }
};

这篇关于OpenLayers 4-适合所选功能的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！