public int ZoomLevel()
{
double zoomLevel = 7;
if (BoundingBox == null)
{
return(7);
}
if (string.IsNullOrEmpty(BoundingBox.WestBoundLongitude) || string.IsNullOrEmpty(BoundingBox.SouthBoundLatitude) ||
string.IsNullOrEmpty(BoundingBox.EastBoundLongitude) || string.IsNullOrEmpty(BoundingBox.NorthBoundLatitude))
{
return(Convert.ToInt16(zoomLevel));
}
GeoCoordinate[] locations = new GeoCoordinate[]
{
new GeoCoordinate(Convert.ToDouble(BoundingBox.SouthBoundLatitude), Convert.ToDouble(BoundingBox.WestBoundLongitude)),
new GeoCoordinate(Convert.ToDouble(BoundingBox.NorthBoundLatitude), Convert.ToDouble(BoundingBox.EastBoundLongitude))
};
double maxLat = -85;
double minLat = 85;
double maxLon = -180;
double minLon = 180;
//calculate bounding rectangle
for (int i = 0; i < locations.Count(); i++)
{
if (locations[i].Latitude > maxLat)
{
maxLat = locations[i].Latitude;
}
if (locations[i].Latitude < minLat)
{
minLat = locations[i].Latitude;
}
if (locations[i].Longitude > maxLon)
{
maxLon = locations[i].Longitude;
}
if (locations[i].Longitude < minLon)
{
minLon = locations[i].Longitude;
}
}
double zoom1 = 0; double zoom2 = 0;
double mapWidth = 1359; //Map width in pixels
double mapHeight = 940; //Map height in pixels
int buffer = 1; //Width in pixels to use to create a buffer around the map. This is to keep pushpins from being cut off on the edge
//Determine the best zoom level based on the map scale and bounding coordinate information
if (maxLon != minLon && maxLat != minLat)
{
//best zoom level based on map width
zoom1 = Math.Log(360.0 / 256.0 * (mapWidth - 2 * buffer) / (maxLon - minLon)) / Math.Log(2);
//best zoom level based on map height
zoom2 = Math.Log(180.0 / 256.0 * (mapHeight - 2 * buffer) / (maxLat - minLat)) / Math.Log(2);
}
//use the most zoomed out of the two zoom levels
zoomLevel = (zoom1 < zoom2) ? zoom1 : zoom2;
return(Convert.ToInt16(zoomLevel));
}
