如何获取用户绘制的圆心的纬度/lang/半径

Question

我正在使用 https://developers.google.com/maps/documentation/javascript/examples/drawing-tools 的这个示例，使用户能够选择一个点并使用户能够在它周围画一个圆。

但是，我还需要：

• 获取用户绘制的圆心的纬度/纬度。
• 获取圆的半径。

• 此外，代码允许用户绘制多个圆，如果可能的话，我需要限制用户只画一个圆，如果用户画另一个圆，则应删除第一个圆。

  
  function initialize() {
    var mapOptions = {
      center: new google.maps.LatLng(-34.397, 150.644),
      zoom: 8
    };
  
  var map = new google.maps.Map(document.getElementById('map-canvas'),
      mapOptions);
  var drawingManager = new google.maps.drawing.DrawingManager({
      drawingMode: google.maps.drawing.OverlayType.MARKER,
      drawingControl: true,
      drawingControlOptions: {
        position: google.maps.ControlPosition.TOP_CENTER,
        drawingModes: [
          google.maps.drawing.OverlayType.MARKER,
          google.maps.drawing.OverlayType.CIRCLE,
          google.maps.drawing.OverlayType.POLYGON,
          google.maps.drawing.OverlayType.POLYLINE,
          google.maps.drawing.OverlayType.RECTANGLE
        ]
      },
      markerOptions: {
        icon: 'images/beachflag.png'
      },
      circleOptions: {
        fillColor: '#ffff00',
        fillOpacity: 1,
        strokeWeight: 5,
        clickable: false,
        editable: true,
        zIndex: 1
      }
    });
    drawingManager.setMap(map);
  }
  google.maps.event.addDomListener(window, 'load', initialize);
  

Answer 1

See http://jsfiddle.net/stevejansen/2HpA6

(function () {
    var circle;
    function initialize() {
        var mapOptions = {
            center: new google.maps.LatLng(-34.397, 150.644),
            zoom: 8
        };

        var map = new google.maps.Map(document.getElementById('map-canvas'),
        mapOptions);
        var drawingManager = new google.maps.drawing.DrawingManager({
            drawingMode: google.maps.drawing.OverlayType.MARKER,
            drawingControl: true,
            drawingControlOptions: {
                position: google.maps.ControlPosition.TOP_CENTER,
                drawingModes: [
                google.maps.drawing.OverlayType.CIRCLE]
            },
            circleOptions: {
                fillColor: '#ffff00',
                fillOpacity: 1,
                strokeWeight: 5,
                clickable: false,
                editable: true,
                zIndex: 1
            }
        });
        drawingManager.setMap(map);
        google.maps.event.addListener(drawingManager, 'circlecomplete', onCircleComplete);
    }
    function onCircleComplete(shape) {
        if (shape == null || (!(shape instanceof google.maps.Circle))) return;
        if (circle != null) {
            circle.setMap(null);
            circle = null;
        }
        circle = shape;
        console.log('radius', circle.getRadius());
        console.log('lat', circle.getCenter().lat());
        console.log('lng', circle.getCenter().lng());
    }
    google.maps.event.addDomListener(window, 'load', initialize);
})();

Answer 2

谷歌地图;

 // Add a circle in Sydney
 Circle circle = map.addCircle(new CircleOptions()
     .center(new LatLng(-33.87365, 151.20689))
     .radius(10000)
     .strokeColor(Color.RED)
     .fillColor(Color.BLUE));
<-- to get radius of any location in map, use this code. It shows the radius value from center of map to x and y coordinates.-->
 Toast.makeText(app.getBaseContext(),***[circle.getRadius()][1]***, 
                Toast.LENGTH_SHORT).show();