Display a map with a predefined initial extent.
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 of the initial map view.
How it works
- Create a
Envelope(xMin, yMin, xMax, yMax, SpatialReference)
. - Create a
Viewpoint
passing in the envelope. - Call
setInitialViewpoint(viewpoint)
on theMap
to set the initial map area.
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=SetInitialMapArea, 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 "SetInitialMapArea.h"
#include "Map.h"
#include "MapQuickView.h"
#include "Basemap.h"
#include "Viewpoint.h"
#include "Envelope.h"
using namespace Esri::ArcGISRuntime;
SetInitialMapArea::SetInitialMapArea(QQuickItem* parent) :
QQuickItem(parent)
{
}
SetInitialMapArea::~SetInitialMapArea() = default;
void SetInitialMapArea::init()
{
qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
qmlRegisterType<SetInitialMapArea>("Esri.Samples", 1, 0, "SetInitialMapAreaSample");
}
void SetInitialMapArea::componentComplete()
{
QQuickItem::componentComplete();
// find QML MapView component
m_mapView = findChild<MapQuickView*>("mapView");
// create a new basemap instance
Basemap* basemap = new Basemap(BasemapStyle::ArcGISImageryStandard, this);
// create a new map instance
m_map = new Map(basemap, this);
// set the initial viewpoint
Envelope envelope(-12211308.778729, 4645116.003309, -12208257.879667, 4650542.535773, SpatialReference(102100));
m_map->setInitialViewpoint(Viewpoint(envelope));
// set map on the map view
m_mapView->setMap(m_map);
}