我怎样才能用 Leaflet.draw 抓取一系列标记？

Question

上下文：

我制作了一张地图，并在其中填充了大约 300 个随机标记。我可以通过单击弹出窗口中的 link 来 'select' 标记，并激活一个选择以显示来自的数据。我也有 Leaflet.draw 插件来绘制圆形、矩形和自定义形状等形状，我想用它来 'select' 几个标记。

问题

如何抓取落在绘制的 leaflet.draw 形状内的标记的传单标记对象，以便进行编辑？我似乎无法进行选择，它要么选择 none 个标记，要么选择所有标记。

代码片段，从不必要的代码中删除：

const drawControl = new L.Control.Draw({
    draw: {
        marker   : false,
        polygon  : true,
        polyline : false,
        rectangle: true,
        circle   : {
            metric: 'metric'
        }
    },
    edit: false
});

const map = L.map('map', {
    layers: [streets, light]
}).setView([CONFIG.MAP.LATITUDE, CONFIG.MAP.LONGITUDE], CONFIG.MAP.ZOOMLEVEL)

map.addControl(drawControl);

map.on(L.Draw.Event.DRAWSTOP, e => {

    const hello = e.target;

    console.log(hello);
    e.target.eachLayer(layer => {
        if (layer.options.icon) {
            console.log(layer);
        }
    });

});

Answer 1

您想要的大部分内容都可以使用 Leaflet 的实用方法轻松完成。如果你想用像 L.Polygon 这样的复杂形状来做到这一点，你将需要像 TurfJS

这样的东西

对于L.Circle，您需要计算圆心之间的距离并将其与半径进行比较：

var marker = new L.Marker(...),
    circle = new L.Circle(...);

var contains = circle.getLatLng().distanceTo(marker.getLatLng()) < circle.getRadius();

对于L.Rectangle，您需要获取它的边界对象并使用包含方法：

var marker = new L.Marker(...),
    rectangle = new L.Rectangle(...);

var contains = rectangle.getBounds().contains(marker.getLatLng());

对于复杂的多边形，我会使用 Turf，但那里有更多的库和插件。下面是一个使用 Turf 的 inside 方法的示例。它以 GeoJSON 点和多边形特征作为参数，因此请注意转换：

var marker = new L.Marker(...),
    polygon = new L.Polygon(...);

var contains = turf.inside(marker.toGeoJSON(), polygon.toGeoJSON());

您可以将它们包装到各自的方便方法中 class:

L.Polygon.include({
    contains: function (latLng) {
        return turf.inside(new L.Marker(latLng).toGeoJSON(), this.toGeoJSON());
    } 
});

L.Rectangle.include({
    contains: function (latLng) {
        return this.getBounds().contains(latLng);
    }
});

L.Circle.include({
    contains: function (latLng) {
        return this.getLatLng().distanceTo(latLng) < this.getRadius();
    }
});

var marker = new L.Marker(...),
    polygon = new L.Polygon(...),
    rectangle = new L.Rectangle(...),
    circle = new L.Circle(...);

polygon.contains(marker.getLatLng());
rectangle.contains(marker.getLatLng());
circle.contains(marker.getLatLng());

请注意，如果您实现了多边形方法，则不需要矩形方法。由于矩形是从多边形扩展而来的，它将继承该方法。我把它留在那儿是为了完整。

现在迭代你的标记并比较它们很容易：

map.on(L.Draw.Event.CREATED, function (e) {
    markers.eachLayer(function (marker) {
        if (!e.layer.contains(marker.getLatLng())) {
            marker.remove();
        }
    });
});

希望对您有所帮助，这是一个有效的片段：

var map = new L.Map('leaflet', {
    'center': [0, 0],
    'zoom': 0
});

var markers = new L.LayerGroup().addTo(map);

for (var i = 0; i < 300; i++) {
    var marker = new L.Marker([
        (Math.random() * (90 - -90) + -90).toFixed(5) * 1,
        (Math.random() * (180 - -180) + -180).toFixed(5) * 1
    ]).addTo(markers);
}

new L.Control.Draw({
    draw: {
        marker   : false,
        polygon  : true,
        polyline : false,
        rectangle: true,
        circle   : {
            metric: 'metric'
        }
    },
    edit: false
}).addTo(map);

L.Polygon.include({
    contains: function (latLng) {
        return turf.inside(new L.Marker(latLng).toGeoJSON(), this.toGeoJSON());
    } 
});

L.Rectangle.include({
    contains: function (latLng) {
        return this.getBounds().contains(latLng);
    }
});

L.Circle.include({
    contains: function (latLng) {
        return this.getLatLng().distanceTo(latLng) < this.getRadius();
    }
});

map.on(L.Draw.Event.CREATED, function (e) {
    markers.eachLayer(function (marker) {
        if (!e.layer.contains(marker.getLatLng())) {
            marker.remove();
        }
    });
});

body {
    margin: 0;
}

html, body, #leaflet {
    height: 100%;
}

<!DOCTYPE html>
<html>
  <head>
    <title>Leaflet 1.0.3</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link type="text/css" rel="stylesheet" href="//unpkg.com/leaflet@1.0.3/dist/leaflet.css" />
    <link type="text/css" rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/leaflet.draw/0.4.9/leaflet.draw.css" />
  </head>
  <body>
    <div id="leaflet"></div>
    <script type="application/javascript" src="//unpkg.com/leaflet@1.0.3/dist/leaflet.js"></script>
    <script type="application/javascript" src="//cdnjs.cloudflare.com/ajax/libs/leaflet.draw/0.4.9/leaflet.draw.js"></script>
    <script type="application/javascript" src="//unpkg.com/@turf/turf@latest/turf.min.js"></script>
  </body>
</html>

Answer 2

感谢@iH8 提供的精彩示例。我进一步避免了

的重复

markers.eachLayer(function (marker) {
    ...
}

并使用标记数组代替其他方法扩展包装器：

首先我注意到 LayerGroup 有一个对象，其键值包含所有标记。我只是使用该对象创建一个标记数组：

// In the on draw event
...
// Set an array containing all the markers
var markers = jsonToArray(layerGroup._layers); 
...

function jsonToArray(jsonObject) {
  var result = [];
  var keys = Object.keys(jsonObject);
  keys.forEach(function (key) {
    result.push(jsonObject[key]);
  });
  return result;
}

然后我用修改后的 contains() 方法重新使用包装器：

  L.Rectangle.include({
    // Single marker case
    contains: function (marker) {
      return this.getBounds().contains(marker.getLatLng());
    },
    // Array of markers
    contains: function (markers) {
      var markersContained = [];
      markers.forEach(marker => {
        markersContained.push(this.getBounds().contains(marker.getLatLng()));
      })
      return markersContained;
    }
  });

  L.Circle.include({
    contains: function (marker) {
      return this.getLatLng().distanceTo(marker.getLatLng()) < this.getRadius();
    },
    contains: function (markers) {
      var markersContained = [];
      markers.forEach(marker => {
        markersContained.push(this.getLatLng().distanceTo(marker.getLatLng()) < this.getRadius());
      })
      return markersContained;
    }
  });

最后在绘制事件中，我检查我的标记是否包含在 :

  map.on(L.Draw.Event.CREATED, function (geometry) {
    // Set an array containing all the markers
    var markers = jsonToArray(layerGroup._layers);

    var result = geometry.layer.contains(markers);
    console.log('result => ', result);
  });

function jsonToArray(jsonObject) {
  var result = [];
  var keys = Object.keys(jsonObject);
  keys.forEach(function (key) {
    result.push(jsonObject[key]);
  });
  return result;
}

var map = new L.Map('leaflet', {
    'center': [0, 0],
    'zoom': 0
});

var layerGroup = new L.LayerGroup().addTo(map);

for (var i = 0; i < 10; i++) {
    var marker = new L.Marker([
        (Math.random() * (90 - -90) + -90).toFixed(5) * 1,
        (Math.random() * (180 - -180) + -180).toFixed(5) * 1
    ]).addTo(layerGroup);
}

new L.Control.Draw({
    draw: {
        marker   : false,
        polygon  : false,
        polyline : false,
        rectangle: true,
        circle   : {
            metric: 'metric'
        }
    },
    edit: false
}).addTo(map);

// Define contains() method for each geometry
L.Rectangle.include({
  contains: function (marker) {
    return this.getBounds().contains(marker.getLatLng());
  },
  contains: function (markers) {
    var markersContained = [];
    markers.forEach(marker => {
      markersContained.push(this.getBounds().contains(marker.getLatLng()));
    })
    return markersContained;
  }
});

L.Circle.include({
  contains: function (marker) {
    return this.getLatLng().distanceTo(marker.getLatLng()) < this.getRadius();
  },
  contains: function (markers) {
    var markersContained = [];
    markers.forEach(marker => {
      markersContained.push(this.getLatLng().distanceTo(marker.getLatLng()) < this.getRadius());
    })
    return markersContained;
  }
});

map.on(L.Draw.Event.CREATED, function (geometry) {
  // Set an array containing all the markers
  var markers = jsonToArray(layerGroup._layers);

  var result = geometry.layer.contains(markers);
  console.log('result => ', result);
});

body {
    margin: 0;
}

html, body, #leaflet {
    height: 100%;
}

<!DOCTYPE html>
<html>
  <head>
    <title>Leaflet 1.0.3</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link type="text/css" rel="stylesheet" href="//unpkg.com/leaflet@1.0.3/dist/leaflet.css" />
    <link type="text/css" rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/leaflet.draw/0.4.9/leaflet.draw.css" />
  </head>
  <body>
    <div id="leaflet"></div>
    <script type="application/javascript" src="//unpkg.com/leaflet@1.0.3/dist/leaflet.js"></script>
    <script type="application/javascript" src="//cdnjs.cloudflare.com/ajax/libs/leaflet.draw/0.4.9/leaflet.draw.js"></script>
  </body>
</html>

Answer 3

我用过：

L.Circle.include({
    contains: function (latLng) {
        return this.getLatLng().distanceTo(latLng) < this.getRadius();
    }
});

边上不在圆内的点也被判断

我怎样才能用 Leaflet.draw 抓取一系列标记？

How can I grab a selection of markers with Leaflet.draw?

javascript

leaflet

leaflet.draw