如何zoom and pan到一个点

private void centerAndZoom(ESRI.ArcGIS.Client.Map map, ESRI.ArcGIS.Client.Geometry.MapPoint mapPoint, double resolution)
{
double ratio = 1.0;
if (map.Resolution != 0.0)
ratio = resolution / map.Resolution;

if (ratio == 1.0)
map.PanTo(mapPoint);
else
{
ESRI.ArcGIS.Client.Geometry.MapPoint mapCenter = map.Extent.GetCenter();
double X = (mapPoint.X - ratio * mapCenter.X) / (1 - ratio);
double Y = (mapPoint.Y - ratio * mapCenter.Y) / (1 - ratio);
map.ZoomToResolution(resolution, new ESRI.ArcGIS.Client.Geometry.MapPoint(X, Y));
}
}