Display a basemap centered at an initial location and scale.
Use case
You can set a map's initial location when you want to highlight a particular feature or area to establish the context.
How to use the sample
When the map loads, note the specific location and scale of the initial map view.
How it works
- Create a
Map
, specifying a basemap style, latitude and longitude in WGS84, and target scale. - Display the map in a map view.
Relevant API
- Basemap
- Map
- MapView
About the data
The map opens with satellite imagery of a guitar-shaped field in the Pampas region of north central Argentina.
Tags
basemap, center, envelope, extent, initial, lat, latitude, level of detail, location, LOD, long, longitude, scale, zoom level
Sample Code
// [WriteFile Name=SetInitialMapLocation, Category=Maps]
// [Legal]
// Copyright 2016 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
// http://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.
// [Legal]
#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD
#include "SetInitialMapLocation.h"
#include "Map.h"
#include "MapQuickView.h"
using namespace Esri::ArcGISRuntime;
SetInitialMapLocation::SetInitialMapLocation(QQuickItem* parent) :
QQuickItem(parent)
{
}
SetInitialMapLocation::~SetInitialMapLocation() = default;
void SetInitialMapLocation::init()
{
qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
qmlRegisterType<SetInitialMapLocation>("Esri.Samples", 1, 0, "SetInitialMapLocationSample");
}
void SetInitialMapLocation::componentComplete()
{
QQuickItem::componentComplete();
// find QML MapView component
m_mapView = findChild<MapQuickView*>("mapView");
// Create a new map with the imagery basemap style enum and set its initial lat, long, and scale
constexpr double lat = -33.867886;
constexpr double lon = -63.985;
constexpr double scale = 9027.977411;
m_map = new Map(BasemapStyle::ArcGISImagery, this);
m_map->setInitialViewpoint(Viewpoint(lat, lon, scale));
// set map on the map view
m_mapView->setMap(m_map);
}