Figure 2. Consume TerraService Web Methods to Return Images.
Many operations are needed to display USGS photos or topo maps from menu selections. City selections or place-name entries invoke the ConvertPlaceToLatLonPt method to return the centerpoint coordinates. Passing the LatLonPt type and image dimensions to GetAreaFromPt generates an AreaBoundingBox type to retrieve the required tile bitmaps. The overridden Form.OnPaint event handler draws the assembled bitmap on the form's active region.