Create a raster layer from a raster image service.
Use case
Accessing a raster image from an online service can be useful for analysing the most up-to-date data available for an area. For example, retrieving recent results of bathymetry surveys within a shipping channel monitored for its sediment build-up would allow planners to assess dredging needs.
How to use the sample
Simply launch the sample to see a raster from an image service being used on a map.
How it works
- Create an
ImageServiceRaster
using the service's URL. - Create a
RasterLayer
from the image service raster. - Add the raster layer to the map.
Relevant API
- ImageServiceRaster
- RasterLayer
About the data
This sample uses a NOAA raster image service. The service computes a bathymetry image from the depth (in meters) of U.S. coastal waters.
Tags
image service, raster
Sample Code
// Copyright 2024 Esri
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import ArcGIS
import SwiftUI
struct AddRasterFromServiceView: View {
/// The error shown in the error alert.
@State private var error: Error?
/// The current draw status of the map.
@State private var currentDrawStatus: DrawStatus = .inProgress
/// A map with a dark gray basemap and a raster layer.
@State private var map: Map = {
let map = Map(basemapStyle: .arcGISDarkGrayBase)
// Creates an initial viewpoint with a coordinate point centered on
// San Francisco's Golden Gate Bridge.
map.initialViewpoint = Viewpoint(
center: Point(x: -13_637_000, y: 4_550_000, spatialReference: .webMercator),
scale: 100_000
)
// Creates a raster from an image service.
let imageServiceRaster = ImageServiceRaster(url: .imageServiceURL)
// Creates a raster layer from the raster.
let rasterLayer = RasterLayer(raster: imageServiceRaster)
map.addOperationalLayer(rasterLayer)
return map
}()
/// The raster layer in the map.
private var rasterLayer: RasterLayer {
map.operationalLayers.first as! RasterLayer
}
var body: some View {
MapView(map: map)
.onDrawStatusChanged { drawStatus in
// Updates the state when the map's draw status changes.
withAnimation {
currentDrawStatus = drawStatus
}
}
.overlay(alignment: .center) {
if currentDrawStatus == .inProgress {
ProgressView("Drawing…")
.padding()
.background(.ultraThinMaterial)
.cornerRadius(10)
.shadow(radius: 50)
}
}
.task {
do {
// Loads a raster layer from online service.
try await rasterLayer.load()
} catch {
// Presents an error message if the raster fails to load.
self.error = error
}
}
.errorAlert(presentingError: $error)
}
}
private extension URL {
static let imageServiceURL = URL(string: "https://gis.ngdc.noaa.gov/arcgis/rest/services/bag_bathymetry/ImageServer")!
}
#Preview {
AddRasterFromServiceView()
}