如何从谷歌地图 api 中查找坐标以在地图中显示数据库中的标记

Question

我有一个搜索页面，我在其中将我的数据库中的属性显示为谷歌地图中的标记。现在我想修改这个搜索页面，以便任何用户都可以在谷歌地图中绘制一个圆形或多边形，并且只会在选定区域（由用户自己绘制）中从我们的数据库中获取属性。到目前为止，我在这里附上我的代码。

图像中的圆圈显示所选区域，结果必须显示所选区域中可用的属性。我的表包含每个属性的纬度和经度 2 个不同的字段。

Javascript 代码：

  <script type="text/javascript">
    var drawingManager;
    var all_overlays = [];
    var selectedShape;
    var colors = ['#1E90FF', '#FF1493', '#32CD32', '#FF8C00', '#4B0082'];
    var selectedColor;
    var colorButtons = {};

    function clearSelection() {
        if (selectedShape) {
            selectedShape.setEditable(false);
            selectedShape = null;
        }
    }

    function setSelection(shape) {
        clearSelection();
        selectedShape = shape;
        shape.setEditable(true);
        selectColor(shape.get('fillColor') || shape.get('strokeColor'));
    }

    function deleteSelectedShape() {
        if (selectedShape) {
            selectedShape.setMap(null);
        }
    }

    function deleteAllShape() {
        for (var i = 0; i < all_overlays.length; i++) {
            all_overlays[i].overlay.setMap(null);
        }
        all_overlays = [];
    }

    function selectColor(color) {
        selectedColor = color;
        for (var i = 0; i < colors.length; ++i) {
            var currColor = colors[i];
            colorButtons[currColor].style.border = currColor == color ? '2px solid #789' : '2px solid #fff';
        }

        // Retrieves the current options from the drawing manager and replaces the
        // stroke or fill color as appropriate.
        var polylineOptions = drawingManager.get('polylineOptions');
        polylineOptions.strokeColor = color;
        drawingManager.set('polylineOptions', polylineOptions);

        var rectangleOptions = drawingManager.get('rectangleOptions');
        rectangleOptions.fillColor = color;
        drawingManager.set('rectangleOptions', rectangleOptions);

        var circleOptions = drawingManager.get('circleOptions');
        circleOptions.fillColor = color;
        drawingManager.set('circleOptions', circleOptions);

        var polygonOptions = drawingManager.get('polygonOptions');
        polygonOptions.fillColor = color;
        drawingManager.set('polygonOptions', polygonOptions);
    }

    function setSelectedShapeColor(color) {
        if (selectedShape) {
            if (selectedShape.type == google.maps.drawing.OverlayType.POLYLINE) {
                selectedShape.set('strokeColor', color);
            } else {
                selectedShape.set('fillColor', color);
            }
        }
    }

    function makeColorButton(color) {
        var button = document.createElement('span');
        button.className = 'color-button';
        button.style.backgroundColor = color;
        google.maps.event.addDomListener(button, 'click', function () {
            selectColor(color);
            setSelectedShapeColor(color);
        });

        return button;
    }

    function buildColorPalette() {
        var colorPalette = document.getElementById('color-palette');
        for (var i = 0; i < colors.length; ++i) {
            var currColor = colors[i];
            var colorButton = makeColorButton(currColor);
            colorPalette.appendChild(colorButton);
            colorButtons[currColor] = colorButton;
        }
        selectColor(colors[0]);
    }

    function initialize() {
        var map = new google.maps.Map(document.getElementById('map'), {
            zoom: 6,
            center: new google.maps.LatLng(22, 77),
            mapTypeId: google.maps.MapTypeId.HYBRID,
            disableDefaultUI: true,
            zoomControl: true
        });

        var polyOptions = {
            strokeWeight: 0,
            fillOpacity: 0.45,
            editable: true
        };
        // Creates a drawing manager attached to the map that allows the user to draw
        // markers, lines, and shapes.
        drawingManager = new google.maps.drawing.DrawingManager({
            drawingMode: google.maps.drawing.OverlayType.POLYGON,
            markerOptions: {
                draggable: true
            },
            polylineOptions: {
                editable: true
            },
            rectangleOptions: polyOptions,
            circleOptions: polyOptions,
            polygonOptions: polyOptions,
            map: map
        });

        google.maps.event.addListener(drawingManager, 'overlaycomplete', function (e) {
            all_overlays.push(e);
            if (e.type != google.maps.drawing.OverlayType.MARKER) {
                // Switch back to non-drawing mode after drawing a shape.
                drawingManager.setDrawingMode(null);

                // Add an event listener that selects the newly-drawn shape when the user
                // mouses down on it.
                var newShape = e.overlay;
                newShape.type = e.type;
                google.maps.event.addListener(newShape, 'click', function () {
                    setSelection(newShape);
                });
                setSelection(newShape);
            }
        });

        // Clear the current selection when the drawing mode is changed, or when the
        // map is clicked.
        google.maps.event.addListener(drawingManager, 'drawingmode_changed', clearSelection);
        google.maps.event.addListener(map, 'click', clearSelection);
        google.maps.event.addDomListener(document.getElementById('delete-button'), 'click', deleteSelectedShape);
        google.maps.event.addDomListener(document.getElementById('delete-all-button'), 'click', deleteAllShape);

        buildColorPalette();
    }
    google.maps.event.addDomListener(window, 'load', initialize);
</script>        

上面的代码包含一些事件来处理搜索页面中的用户交互以在选定区域中绘制圆、多边形到搜索属性。

图像中的显示属性按钮必须在所选区域中显示属性标记。

我如何获得选定的圆形或多边形区域的纬度和经度？
我将如何查询我的数据库中的坐标范围？

非常感谢您的热心帮助...

Answer 1

我想自从您发布此问题以来，您已经找到了解决方案。 但是，如果其他人需要答案，您可以通过以下方式获取绘图多边形的纬度/经度：

google.maps.event.addDomListener(drawingManager, 'polygoncomplete', function(polygon) {
    var polygonBounds = polygon.getPath();
}

多边形的每个顶点的边界现在都在polygonBounds 中，只需对其进行迭代并使用 lat / lng 做你想做的事

对于一个圆，你只需要中心的 lat / lng 和它的半径

google.maps.event.addListener(drawingManager, 'circlecomplete', function(circle) {
        var radius = circle.getRadius();
        var center = circle.getCenter();
}

希望对大家有所帮助

PS : 我使用的是 GoogleMaps v3.14，我从未使用其他版本进行测试。