编辑：

Question

我正在研究一些地图的东西，而且我遇到了一些似乎非常基本的东西。

我正在做的是为地图添加10个标志，我需要根据引脚的位置动态设置地图的缩放级别和中心（地图需要放大到远处）可能仍然显示所有引脚）。

这与MultiMap完全一样，没有任何干预（正如预期的那样），但Virtual Earth地图效果不佳。如果我没有给它一个中心Lat / Lon，它默认显示所有美国。

任何人都可以指出我正确的方向，以使这个工作？

编辑：

好的，我可以通过在我的MVC控制器中使用以下内容来计算正确的中心

''# we're going to rock the AVERAGE LAT/LON here
Dim eventCount As Integer = 0
Dim totalLat As Double = 0
Dim totalLon As Double = 0
For Each mel In MapEventList
    totalLat += mel.lat
    totalLon += mel.lon
    eventCount += 1
Next
ViewData("centerLat") = totalLat / eventCount
ViewData("centerLon") = totalLon / eventCount

现在我只是试图计算最佳缩放级别

编辑2：

所以我从控制器中删除了计算并将其添加到我的Javascript中。脚本的重量很轻，但会由客户端计算机而不是我的服务器完成计算（如果/当网站开始获得大量点击时有价值）

$(document).ready(function () {
    // Load the Bing Map and populate it
    var increment = 0; // used to increment event locations
    var sumLat = 0; // used to find the average LAT location
    var sumLon = 0; // used to find the average LON location

    // Load the initial map
    LoadMap();

    // loop through all events and place a point on the map
    // also add to the sumLat and sumLon variable
    $.each(json_object, function () {
        increment = ++increment;
        sumLat = sumLat + this.lat;
        sumLon = sumLon + this.lon;
        LoadPoint(this.lat, this.lon, this.title, this.desc, increment);
    });

    // find the averate Lat and Lon for map centering
    var centerLat = sumLat / increment;
    var centerLon = sumLon / increment;
    LatLon = new VELatLong(centerLat, centerLon);

    // Set the new map Center based on the average of all points.
    map.SetCenter(LatLon)
});

function LoadMap() {
    map = new VEMap('bingMap');
    mapOptions = new VEMapOptions

    // sets map options for asthetics
    mapOptions.DashboardColor = "black";
    mapOptions.EnableDashboardLabels = false;
    mapOptions.EnableBirdseye = false;
    mapOptions.EnableDashboardLabels = false;

    // Load the initial map
    // note: the LatLon is "null" at this point because we are going to 
    // center the map later based on the average of all points.
    map.LoadMap(null, zoomLevel, null, null, null, false, null, mapOptions);

};

function LoadPoint(lat, lon, title, desc, pinId) {
    var point = new VELatLong(lat, lon);
    var pin = new VEShape(VEShapeType.Pushpin, point);
    pin.SetTitle(title);
    pin.SetDescription(desc + "<br /><br />lat: " + lat + " lon: " + lon);
    pin.SetCustomIcon("<div class='pinStyle'><div class='pinText'>" + pinId + "</div></div>");
    map.AddShape(pin);
};

但是我仍然在努力计算最佳缩放级别

Answer 1

如果您使用的是javascript版本，那么您不需要计算它，您可以直接将VELatLong对象数组提供给VEMap.SetMapView，它将居中+缩放以便所有引脚都可见。

Answer 2

当我遇到类似的问题时，我通过计算（粗略）针脚的质心来解决它。我说“粗糙”因为我只是平均每个点的纬度/经度而这是不正确的，因为地球是一个球体。

Answer 3

非常感谢@wildpeaks获得答案。我已将结果发布在其他需要朝正确方向推进的人身上。

$(document).ready(function () {
    // Load the Bing Map and populate it
    var increment = 0; // used to increment event locations
    var sumLat = 0; // used to find the average LAT location
    var sumLon = 0; // used to find the average LON location
    var latlonArray = new Array();  // used to create an Array of lat and lon in order to "SetMapView"

    // Load the initial map
    LoadMap();

    // loop through all events and place a point on the map
    // also add to the sumLat and sumLon variable
    $.each(json_object, function () {
        latlonArray[increment] = new VELatLong(this.lat, this.lon); // Add to the array before the increment
        increment = ++increment;
        sumLat = sumLat + this.lat;
        sumLon = sumLon + this.lon;
        LoadPoint(this.lat, this.lon, this.title, this.desc, increment);
    });

    // find the averate Lat and Lon for map centering
    var latlonCenter = new VELatLong(sumLat / increment, sumLon / increment);

    // Set the new map Center based on the average of all points.
    map.SetCenter(latlonCenter);
    map.SetMapView(latlonArray); // pass the latlonArray object to the SetMapView in order to display all map pins appropriately.

});

虚拟地球/ Bing地图 - 如何计算最佳缩放级别

编辑：

编辑2：

但是我仍然在努力计算最佳缩放级别

3 个答案: