Turf.buffer和可拖动标记 [英] Turf.buffer and a draggable marker

问题描述

到目前为止，我已经创建了一个标记，将其传输到geoJSON，并使用Turf.buffer在其周围创建了一个缓冲区.在地图上拖动缓冲区时，如何使它粘"在标记上?

So far I have created a marker, transfered it to geoJSON, and created a buffer around it with Turf.buffer. How can I get this buffer to "stick" to the marker as I drag it around the map?

   <script>
        L.mapbox.accessToken = 'fg.eyJ1IjoisdflksdaklsjZWwiLCJhIjoiRHNwX0ZWNCJ9.Ov2O5sslkdqV93_R0lq3Q';
        var map = L.mapbox.map('map', 'example.kf6j9ec4')
            .setView([38.633, -90.319],12);

        var marker = L.marker(new L.LatLng(38.633, -90.319), {
            icon: L.mapbox.marker.icon({
                'marker-color': '1B05E3', 
                "marker-symbol": "pitch"
            }),
            draggable: true
        });

        marker.bindPopup('This marker is draggable! Move it around to see what locales are in your "area of walkability".');

        //Make the marker a feature
        var pointMarker = marker.toGeoJSON();

        //buffer the marker geoJSON feature
        var buffered = turf.buffer(pointMarker, 2, 'miles');

        var resultFeatures = buffered.features.concat(pointMarker);
        var result = {
            "type": "FeatureCollection",
            "features": resultFeatures
        };

        L.mapbox.featureLayer().setGeoJSON(buffered).addTo(map);
        marker.addTo(map);

    </script>

推荐答案

因此，在上述代码的帮助下，通过大量的搜索，我提出了一个可行的解决方案.起作用的方法:添加可拖动标记，然后使用"marker.on"方法启动清除所有旧缓冲区的函数，然后使用函数在当前位置周围重画缓冲区.

So with the help of the above code and a lot of googling I came up with a solution which works. What worked: adding a draggable marker and then using the "marker.on" method to initiate a function to clear any old buffers and then a function to redraw the buffer around the current location.

        //add marker that is draggable
        var marker = L.marker(new L.LatLng(38.633, -90.319), {
            icon: L.mapbox.marker.icon({
                'marker-color': '1B05E3', 
                "marker-symbol": "pitch"
            }),
            draggable: true
        });

        //add marker popup
        marker.bindPopup('This marker is draggable! Move it around to see what locales are in your "area of walkability".');
        marker.addTo(map);

        //remove old buffers (used when marker is dragged)
        function removeBuff(){
            map.removeLayer(buff);
            };

        //create buffer (used when the marker is dragged)
        function updateBuffer(){
            //Make the marker a feature
            var pointMarker = marker.toGeoJSON();
            //buffer the marker geoJSON feature
            var buffered = turf.buffer(pointMarker, 1, 'miles');
            //add buffer to the map. Note: no "var" before "buff" makes it a global variable and usable within the removeBuff() function. 
            buff = L.mapbox.featureLayer(buffered);
            buff.addTo(map);
        };

        marker.on('drag', function(){removeBuff(), updateBuffer()});
        updateBuffer();

这篇关于Turf.buffer和可拖动标记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！