Google Map API 如何为当前位置设置标记

Question

我正在学习 google map API，当我尝试将当前坐标添加到数组时遇到了这个问题。这是我的代码：

var locations = [];

在 initialize() 中我有：

function initialize() {
    infowindow = new google.maps.InfoWindow();
    var myOptions = {
        zoom: 10,
        mapTypeControl: true,
        navigationControl: true,
    }
    map = new google.maps.Map(document.getElementById("map"), myOptions);

    add_location('Place 1', 37.2846372, -123.3270422);
    set_current_location();
    set_markers(new google.maps.LatLngBounds(), map);
}

第一个标记已设置，而 set_current_location() 似乎不起作用。以下是其余代码：

// add new location to the locations array
function add_location(description, lastitude, longtitude) {
    locations.push([description, lastitude, longtitude]);
}

// Set all the markers in the location arrays and bound/frame the map
function set_markers(bounds, map) {
    for (i = 0; i < locations.length; i++) {
        marker = new google.maps.Marker({
            position: new google.maps.LatLng(locations[i][1], locations[i][2]),
            map: map
        });
        bounds.extend(marker.position);
        google.maps.event.addListener(marker, 'click', (function (marker, i) {
            return function () {
                infowindow.setContent(locations[i][0]);
                infowindow.open(map, marker);
            }
        })(marker, i));
    }
    map.fitBounds(bounds);
}

// Get current location based on the IP Address
function set_current_location() {
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(function (position) {
            var pos = new google.maps.LatLng(position.coords.latitude,
            position.coords.longitude);
            var myLat = position.coords.latitude;
            var myLong = position.coords.longitude;
            add_location('My location', position.coords.latitude, position.coords.longitude);
        });
    } else {
        alert("Geolocation is not supported by this browser.");
    }
}

谁能帮助或给我一个提示？我想将当前位置添加到位置数组中，这样我就可以跟踪我添加了多少位置。非常感谢。

Answer 1

如果您只是将set_markers() 移动到getCurrentPosition() 的success 回调的末尾并且用户拒绝分享他的位置，您将不会获得地图，而只会获得灰色区域。没有为您的地图设置center，这是必需的属性。最好这样定义：

var myOptions = {
    zoom: 10,
    center: new google.maps.LatLng(37.339386, -121.894955),
    mapTypeControl: true,
    navigationControl: true,
}
map = new google.maps.Map(document.getElementById("map"), myOptions);
...

另外，你也可以在getCurrentPosition()的error回调结束时调用set_markers()，这样万一用户拒绝分享他的位置，你可以显示可用位置：

// Get current location based on the IP Address
function set_current_location() {
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(function (position) {
            /*
            var pos = new google.maps.LatLng(position.coords.latitude,
                                             position.coords.longitude);
            var myLat = position.coords.latitude;
            var myLong = position.coords.longitude;
            */
            add_location('My location', 
                        position.coords.latitude, 
                        position.coords.longitude);

            set_markers(new google.maps.LatLngBounds(), map);
        }, function error(err) {
            console.log('error: ' + err.message);
            set_markers(new google.maps.LatLngBounds(), map);            
        });
    } else {
        alert("Geolocation is not supported by this browser.");
    }
}

见example at jsbin