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我正在使用 OpenLayers3 并希望拥有用户可以绘制 1 个或多个点的地图。我已经实现了。但是，我还想保存每个点的坐标。

但我真的不知道该怎么做，因为 OpenLayers3 相当新，而且我很难在网上找到示例。

这是我到目前为止所拥有的：

var modeSelect = document.getElementById('type');
var draw; // global so we can remove it later

//modify 
var featureOverlay = new ol.FeatureOverlay({
  style: new ol.style.Style({
    fill: new ol.style.Fill({
      color: 'rgba(255, 255, 255, 0.2)'
    }),
    stroke: new ol.style.Stroke({
      color: '#ffcc33',
      width: 2
    }),
    image: new ol.style.Circle({
      radius: 7,
      fill: new ol.style.Fill({
        color: '#ffcc33'
      })
    })
  })
});
featureOverlay.setMap(map);
// modify end

function addInteraction() {
    var value = modeSelect.value;
    if (value == 'Point') {
        draw = new ol.interaction.Draw({
          //source: source,
          features: featureOverlay.getFeatures(),
          type: /** @type {ol.geom.GeometryType} */ (value)
        });
        map.addInteraction(draw);
    }
    // modify
    if (value == 'Modify') {
        var modify = new ol.interaction.Modify({
            features: featureOverlay.getFeatures(),
            // the SHIFT key must be pressed to delete vertices, so
            // that new vertices can be drawn at the same position
            // of existing vertices
            deleteCondition: function(event) {
            return ol.events.condition.shiftKeyOnly(event) &&
                ol.events.condition.singleClick(event);
          }
        });
        map.addInteraction(modify);
    } 
}
addInteraction();
4

1 回答 1

0

好的。我想出了一个至少是朝着正确方向迈出的一步的解决方案。我总体上重新排列了代码并实现了这个功能：

function saveData() {
    // save it as geojson
    var format = new ol.format['GeoJSON']();
    // this will be the data in the chosen format
    var data;

    try {
    // convert the data of the vector_layer into the chosen format
    data = format.writeFeatures(vector_layer.getSource().getFeatures());
    } catch (e) {
    // at time of creation there is an error in the GPX format (18.7.2014)
    $('#data').val(e.name + ": " + e.message);
    return;
    }

    $('#data').val(JSON.stringify(data, null, 4));

}

不过，我仍在努力将其写入服务器上的实际 .json 文件，但我非常有信心找到解决方案。

编辑：

其实很简单。刚刚写了这段 php 来完成所有的工作：

    <?php

    include 'dbconnection.php';


        $str="INSERT INTO multipoint_tabelle (id, geom) VALUES (1,(SELECT ST_Multi(ST_Union(geom)) FROM punkttabelle));";
        $test_str=pg_query($conn, $str);


    // write GeoJSON 

        $json = $_POST['json'];
        //$points_coords = $_POST['coords'];

        if (json_decode($json) != null) { /* sanity check */

        // w+ Read/Write. Opens and clears the contents of file; or creates a new file if it doesn't exist
            $file = fopen('points.json','w+');
            fwrite($file, $json);
            fclose($file);
        } else {

        // handle error 
        }


?>
于 2014-09-22T14:56:06.983 回答