计算 C# 中谷歌地图控件的缩放级别

Question

I'm using GoogleMap Control have a collection of markers with Geo locations. I can calculate the min and max lat longs and find the center point on where to center the map but I also need to calculate the zoom level programmatically. Does anyone how to do this?

Answer 1

If your using v3 then simply

var bounds = new google.maps.LatLngBounds();

then extend your bounds for each marker:

bounds.extend(myLatLng);

and use this to automatically position and zoom

map.fitBounds(bounds);

Answer 2

Found this on an issue page of the GoogleMap Control project site. You have to inject javascript to do it.

    // Set the map to call zoomMap javascriptFunction
    GoogleMap.OnClientMapLoad = "zoomMap";

    // build zoomMap javascript function. I already know what my bounds are
    StringBuilder script = new StringBuilder();
    script.AppendFormat("<script>").AppendLine();
    script.Append("function zoomMap() {").AppendLine();
    script.AppendFormat("var sw = new GLatLng({0}, {1});", minLat, minLong).AppendLine();
    script.AppendFormat("var ne = new GLatLng({0}, {1});", maxLat, maxLong).AppendLine();
    script.AppendFormat("var bounds = new GLatLngBounds(sw, ne);").AppendLine();
    script.AppendFormat("var zoomLevel = GoogleMap.GMap.getBoundsZoomLevel(bounds);").AppendLine();
    script.AppendFormat("GoogleMap.GMap.setZoom(zoomLevel);", GoogleMap.ClientID).AppendLine();
    script.Append("}").AppendLine();
    script.AppendFormat("</script>").AppendLine();

    Page.RegisterClientScriptBlock("map", script.ToString());