Projection

This GeoBlazor sample, written in Blazor for .NET developers, demonstrates how the same geometry looks under different map projections, using GeoBlazor's MapView and SpatialReference Razor components together with the ArcGIS Maps SDK for JavaScript GeoJSONLayer and a custom JavaScript hook into the GeometryEngine. The page shows a 2D world map of country polygons (from an Esri-hosted GeoJSON service) drawn over a light-blue background with a dashed rectangular extent outline. In the upper-right corner of the map a CustomOverlay holds a grouped projection dropdown organized by category (Equidistant, Conformal, Equal-area, Gnomonic, Compromise) listing options such as WGS84, World Cassini, World Equidistant Conic, World Stereographic, World Eckert VI, World Sinusoidal, North Pole Gnomonic, Web Mercator, World Gall Stereographic, World Winkel Tripel, and the Fuller / Dymaxion polyhedral map. Selecting a projection calls MapView.SetSpatialReference and the entire view reprojects on the fly. Hovering over the map invokes a custom JS extension that draws a 1000-kilometer geodesic buffer at the pointer so the user can see how distance and area distort across the chosen projection, and a popup in the lower-left corner shows the WKID and X/Y of the view center. The sample is intended to demonstrate live spatial-reference switching and JS interop in a Blazor application without writing JavaScript for the main page logic.