Display an offline map (on demand) | ArcGIS Maps SDK for Qt

Learn how to download and display an offline map An offline map is a map area and its data content downloaded from an offline-enabled web map for use in offline applications built with ArcGIS Maps SDKs for Native Apps. Learn more for a user-defined geographical area of a web map A web map is a map stored as a JSON object that defines properties such as the basemap layer, data layers, layer styles, and pop-up styles. Its JSON structure is defined by the web map specification. Learn more .

Map centered on Naperville with utility features, route sketches, and a red offline download extent.

Offline maps An offline map is a map area and its data content downloaded from an offline-enabled web map for use in offline applications built with ArcGIS Maps SDKs for Native Apps. Learn more allow users to continue working when network connectivity is poor or lost. If a web map A web map is a map stored as a JSON object that defines properties such as the basemap layer, data layers, layer styles, and pop-up styles. Its JSON structure is defined by the web map specification. Learn more is enabled for offline use, a user can request that ArcGIS generates an offline map for a specified geographic area of interest.

In this tutorial, you will download an offline map An offline map is a map area and its data content downloaded from an offline-enabled web map for use in offline applications built with ArcGIS Maps SDKs for Native Apps. Learn more for an area of interest from the web map A web map is a map stored as a JSON object that defines properties such as the basemap layer, data layers, layer styles, and pop-up styles. Its JSON structure is defined by the web map specification. Learn more of the stormwater network within Naperville, IL, USA . You can then use this offline map without a network connection.

Prerequisites

Before starting this tutorial:

You need an ArcGIS Location Platform or ArcGIS Online account.
Your system meets the system requirements.
The ArcGIS Maps SDK for Qt, version 300.1.0 or later is installed.
The Qt 6.8.2 software development framework or later is installed.
The CMake build system is installed.

Get the web map item ID

You can use ArcGIS tools Tools, also known as developer tools, are ArcGIS software applications such as portal and ArcGIS Pro that developers can use to prepare content and data for custom applications they are building. Learn more to create and view web maps A web map is a map stored as a JSON object that defines properties such as the basemap layer, data layers, layer styles, and pop-up styles. Its JSON structure is defined by the web map specification. Learn more . Use the Map Viewer Map Viewer is a browser-based mapping tool that can view, create, and save web maps. It can also perform mapping, visualization, and spatial analysis operations. Learn more to identify the web map item ID An item ID is a unique identifier representing a single item stored, managed, and accessed in a portal, such as a web map, hosted layer, or file. Learn more . This item ID will be used later in the tutorial.

Go to the Naperville water network in the Map Viewer Map Viewer is a browser-based mapping tool that can view, create, and save web maps. It can also perform mapping, visualization, and spatial analysis operations. Learn more in ArcGIS Online ArcGIS Online is a GIS mapping, analytics, data hosting, and content management software as a service (SaaS) product. It includes applications, tools, APIs, and location services for users and developers. It is subscription-based and requires an ArcGIS Online account. Learn more . This web map A web map is a map stored as a JSON object that defines properties such as the basemap layer, data layers, layer styles, and pop-up styles. Its JSON structure is defined by the web map specification. Learn more displays stormwater network within Naperville, IL, USA .
Make a note of the item ID An item ID is a unique identifier representing a single item stored, managed, and accessed in a portal, such as a web map, hosted layer, or file. Learn more at the end of the browser’s URL. The item ID should be:
acc027394bc84c2fb04d1ed317aac674

Develop or Download

You have two options for completing this tutorial:

Option 1: Develop the code or
Option 2: Download the completed solution

Option 1: Develop the code

Open a Qt Creator project

Open the project you created by completing the Display a map tutorial.

Continue with the following instructions to display an offline map.

Update the header file

You can display a web map A web map is a map stored as a JSON object that defines properties such as the basemap layer, data layers, layer styles, and pop-up styles. Its JSON structure is defined by the web map specification. Learn more using the web map’s item ID An item ID is a unique identifier representing a single item stored, managed, and accessed in a portal, such as a web map, hosted layer, or file. Learn more . Create a map A map is a collection of layers that are displayed in 2D. It is typically composed of a basemap layer and data layers. Learn more from the web map portal item An item, also known as a content item, is a resource stored in a portal such as a web map, hosted layer, style, script tool, file, or notebook. Learn more , and display it in your app.

In the project Display_a_map > Display_a_map > Header Files folder of Qt Creator, double-click the Display_a_map.h file to open it. Add the following classes to the header file.

Display_a_map.h

namespace Esri::ArcGISRuntime {

class Map;

class MapQuickView;

class PortalItem;
class OfflineMapTask;

Remove the unnecessary declaration for the setViewpoint() function.

Display_a_map.h

private:
    Esri::ArcGISRuntime::MapQuickView* mapView() const;
    void setMapView(Esri::ArcGISRuntime::MapQuickView* mapView);

    void setupViewpoint();

    Esri::ArcGISRuntime::Map* m_map = nullptr;

    Esri::ArcGISRuntime::MapQuickView* m_mapView = nullptr;

};

Add the generateMapByExtent() function declaration and member variables m_portalItem and m_offlineMapTask. Then save the file.

Display_a_map.h

private:
    Esri::ArcGISRuntime::MapQuickView* mapView() const;
    void setMapView(Esri::ArcGISRuntime::MapQuickView* mapView);

    void generateMapByExtent();

    Esri::ArcGISRuntime::Map* m_map = nullptr;

    Esri::ArcGISRuntime::MapQuickView* m_mapView = nullptr;

    Esri::ArcGISRuntime::PortalItem* m_portalItem = nullptr;
    Esri::ArcGISRuntime::OfflineMapTask* m_offlineMapTask = nullptr;

Update include statements

In the project Display_a_map > Display_a_map > Source Files folder of Qt Creator, double-click the Display_a_map.cpp file to open it. Remove the following unneeded include statements (MapTypes.h, Point.h, and Viewpoint.h).

Display_a_map.cpp

#include "Display_a_map.h"
#include "Map.h"

#include "MapTypes.h"

#include "MapQuickView.h"

#include "Point.h"
#include "Viewpoint.h"

#include "SpatialReference.h"
#include <QFuture>

Add the following new include statements. Then save the file.

Display_a_map.cpp

#include "Display_a_map.h"
#include "Map.h"

#include "MapQuickView.h"

#include "SpatialReference.h"
#include <QFuture>

#include "Envelope.h"
#include "EnvelopeBuilder.h"
#include "Error.h"
#include "GenerateOfflineMapParameters.h"
#include "GenerateOfflineMapJob.h"
#include "GenerateOfflineMapResult.h"
#include "Graphic.h"
#include "GraphicListModel.h"
#include "GraphicsOverlay.h"
#include "GraphicsOverlayListModel.h"
#include "OfflineMapTask.h"
#include "Portal.h"
#include "PortalItem.h"
#include "SimpleFillSymbol.h"
#include "SimpleLineSymbol.h"
#include "SymbolTypes.h"
#include "TaskTypes.h"
#include <QDir>
#include <QUuid>

Remove remaining unneeded code

At this point we will remove the additional unnecessary code before we add the logic for the rest of the app.

Continuing on the Display_a_map.cpp file, remove the setupViewpoint() method.

Display_a_map.cpp

void Display_a_map::setupViewpoint()
{

    const Point center(-118.80543, 34.02700, SpatialReference::wgs84());
    const Viewpoint viewpoint(center, 100000.0);
    m_mapView->setViewpointAsync(viewpoint);

}

Remove the call to the setupViewpoint() method from within the setMapView(MapQuickView* mapView) function.

Display_a_map.cpp

// Set the view (created in QML)
void Display_a_map::setMapView(MapQuickView* mapView)
{
    if (!mapView || mapView == m_mapView)
    {
        return;
    }

    m_mapView = mapView;

    m_mapView->setMap(m_map);

    setupViewpoint();

    emit mapViewChanged();
}

Update the constructor

At this point you will update the constructor in the app.

Continuing in the Display_a_map.cpp file, remove the comma after QObject(parent) and then modify the constructor to remove initialization with BasemapStyle and the Map.

Display_a_map.cpp

Display_a_map::Display_a_map(QObject* parent /* = nullptr */):

    QObject(parent),

    m_map(new Map(BasemapStyle::ArcGISTopographic, this))

Inside the body of the constructor, add code to Instantiate a Portal and from that, a PortalItem using the web map item ID for the Naperville water network. Use that to create a new Map. Then create a new OfflineMapTask referencing that portal item. Then save the file.

Display_a_map.cpp

Display_a_map::Display_a_map(QObject* parent /* = nullptr */):

    QObject(parent)

{

    // Create a portal instance and portal item for the offline map.
    Portal* portal = new Portal(false, this);
    m_portalItem = new PortalItem(portal, "acc027394bc84c2fb04d1ed317aac674", this);

    // Create a map using the portal item.
    m_map = new Map(m_portalItem, this);

    // Create an offline map task using the portal item.
    m_offlineMapTask = new OfflineMapTask(m_portalItem, this);

Specify the area of the web map to take offline

Continuing in the Display_a_map.cpp file, add the call to generateMapByExtent() method within the setMapView(MapQuickView* mapView) function. The next step implements this method.

Display_a_map.cpp

// Set the view (created in QML)
void Display_a_map::setMapView(MapQuickView* mapView)
{
    if (!mapView || mapView == m_mapView)
    {
        return;
    }

    m_mapView = mapView;

    m_mapView->setMap(m_map);

    generateMapByExtent();

    emit mapViewChanged();
}

At the end of the code file, begin to implement the generateMapByExtent() function. Use EnvelopeBuilder to set four parameters and then call toEnvelope() to create the envelope. Add this new function near the bottom of the file.

Display_a_map.cpp

void Display_a_map::generateMapByExtent()
{
    // Create envelope to define area of interest.
    EnvelopeBuilder* envelopeBuilder = new EnvelopeBuilder(SpatialReference::wgs84(), this);
    envelopeBuilder->setXMin(-88.1526);
    envelopeBuilder->setXMax(-88.1490);
    envelopeBuilder->setYMin(41.7694);
    envelopeBuilder->setYMax(41.7714);

    // Convert the envelope builder to an envelope object.
    Envelope offlineArea = envelopeBuilder->toEnvelope();

}

Add a graphic to generateMapByExtent() to show the area you will take offline. Create a Graphic using the envelope, SimpleFillSymbol and SimpleLineSymbol. From this create a GraphicsOverlay and add it to the mapView. Then save the file.

Display_a_map.cpp

void Display_a_map::generateMapByExtent()
{
    // Create envelope to define area of interest.
    EnvelopeBuilder* envelopeBuilder = new EnvelopeBuilder(SpatialReference::wgs84(), this);
    envelopeBuilder->setXMin(-88.1526);
    envelopeBuilder->setXMax(-88.1490);
    envelopeBuilder->setYMin(41.7694);
    envelopeBuilder->setYMax(41.7714);

    // Convert the envelope builder to an envelope object.
    Envelope offlineArea = envelopeBuilder->toEnvelope();

    // Create a graphic to visually represent the offline area.
    Graphic* box = new Graphic(offlineArea, new SimpleFillSymbol(
        SimpleFillSymbolStyle::Solid, Qt::transparent,
        new SimpleLineSymbol(SimpleLineSymbolStyle::Solid, Qt::red, 3, this), this), this);

    // Create a graphics overlay to hold the graphic.
    GraphicsOverlay* boxOverlay = new GraphicsOverlay(this);

    // Add the graphic to the graphics overlay.
    boxOverlay->graphics()->append(box);

    // Add the graphics overlay to the map view.
    m_mapView->graphicsOverlays()->append(boxOverlay);

}

Download and display the offline map

Continuing in the Display_a_map.cpp file, add the following createDefaultGenerateOfflineMapParametersAsync method that creates a GenerateOfflineMapParameters object. These offline map parameters will serve as the input to create a GenerateOfflineMapJob. Store the resulting offline mobile map package (MMPK) in a location on your development machine.

IMPORTANT: specify the folder location that exists on the device and that it matches the code for the outputPath variable.

Display_a_map.cpp

void Display_a_map::generateMapByExtent()
{
    // Create envelope to define area of interest.
    EnvelopeBuilder* envelopeBuilder = new EnvelopeBuilder(SpatialReference::wgs84(), this);
    envelopeBuilder->setXMin(-88.1526);
    envelopeBuilder->setXMax(-88.1490);
    envelopeBuilder->setYMin(41.7694);
    envelopeBuilder->setYMax(41.7714);

    // Convert the envelope builder to an envelope object.
    Envelope offlineArea = envelopeBuilder->toEnvelope();

    // Create a graphic to visually represent the offline area.
    Graphic* box = new Graphic(offlineArea, new SimpleFillSymbol(
        SimpleFillSymbolStyle::Solid, Qt::transparent,
        new SimpleLineSymbol(SimpleLineSymbolStyle::Solid, Qt::red, 3, this), this), this);

    // Create a graphics overlay to hold the graphic.
    GraphicsOverlay* boxOverlay = new GraphicsOverlay(this);

    // Add the graphic to the graphics overlay.
    boxOverlay->graphics()->append(box);

    // Add the graphics overlay to the map view.
    m_mapView->graphicsOverlays()->append(boxOverlay);

    // Generate the offline map parameters.
    m_offlineMapTask->createDefaultGenerateOfflineMapParametersAsync(offlineArea).then(
        this,[this](const GenerateOfflineMapParameters& params)
    {

        // Generate the offline map. Store the .mmpk in the desired location.
        // IMPORTANT: Replace "ENTER_PATH_TO_MMPK_FILE" with the actual path where you want to save the .mmpk file.
        const QString outputPath = "ENTER_PATH_TO_MMPK_FILE/offlinemap.mmpk"; // Ex: "C:/mmpk_folder/offlinemap.mmpk"

        GenerateOfflineMapJob* generateJob = m_offlineMapTask->generateOfflineMap(params, outputPath);

        // Check if the generate job was created successfully.
        if (!generateJob)
            return;

}

Add a connect that monitors the status of the GenerateOfflineMapJob and returns changes to status.

Display_a_map.cpp

void Display_a_map::generateMapByExtent()
{
    // Create envelope to define area of interest.
    EnvelopeBuilder* envelopeBuilder = new EnvelopeBuilder(SpatialReference::wgs84(), this);
    envelopeBuilder->setXMin(-88.1526);
    envelopeBuilder->setXMax(-88.1490);
    envelopeBuilder->setYMin(41.7694);
    envelopeBuilder->setYMax(41.7714);

    // Convert the envelope builder to an envelope object.
    Envelope offlineArea = envelopeBuilder->toEnvelope();

    // Create a graphic to visually represent the offline area.
    Graphic* box = new Graphic(offlineArea, new SimpleFillSymbol(
        SimpleFillSymbolStyle::Solid, Qt::transparent,
        new SimpleLineSymbol(SimpleLineSymbolStyle::Solid, Qt::red, 3, this), this), this);

    // Create a graphics overlay to hold the graphic.
    GraphicsOverlay* boxOverlay = new GraphicsOverlay(this);

    // Add the graphic to the graphics overlay.
    boxOverlay->graphics()->append(box);

    // Add the graphics overlay to the map view.
    m_mapView->graphicsOverlays()->append(boxOverlay);

    // Generate the offline map parameters.
    m_offlineMapTask->createDefaultGenerateOfflineMapParametersAsync(offlineArea).then(
        this,[this](const GenerateOfflineMapParameters& params)
    {

        // Generate the offline map. Store the .mmpk in the desired location.
        // IMPORTANT: Replace "ENTER_PATH_TO_MMPK_FILE" with the actual path where you want to save the .mmpk file.
        const QString outputPath = "ENTER_PATH_TO_MMPK_FILE/offlinemap.mmpk"; // Ex: "C:/mmpk_folder/offlinemap.mmpk"

        GenerateOfflineMapJob* generateJob = m_offlineMapTask->generateOfflineMap(params, outputPath);

        // Check if the generate job was created successfully.
        if (!generateJob)
            return;

        // Use connect to monitor job status for changes and return job status.
        connect(generateJob, &GenerateOfflineMapJob::statusChanged, this, [this, generateJob]()
                {
                    // Check the job status and handle accordingly.
                    if (generateJob->jobStatus() == JobStatus::Succeeded)
                    {
                        // The offline map has been successfully generated.
                        qDebug() << "generating offline map";

                        // Set the generated offline map to the map view.
                        m_mapView->setMap(generateJob->result()->offlineMap(this));

                        // Output any errors that occurred during the generation process.
                        qDebug() << (generateJob->error().isEmpty() ? "No errors" :
                         (generateJob->error().message() + generateJob->error().additionalMessage()));
                    }

                    // Handle other job statuses if necessary.
                    else if (generateJob->jobStatus() == JobStatus::Failed)
                    {
                        qWarning() << generateJob->error().message() << generateJob->error().additionalMessage();
                    }
                });

}

Finally, add another connect that displays progress of the GenerateOfflineMapJob as the job executes. Then add code for the generateJob->start(). Then save the file.

Display_a_map.cpp

void Display_a_map::generateMapByExtent()
{
    // Create envelope to define area of interest.
    EnvelopeBuilder* envelopeBuilder = new EnvelopeBuilder(SpatialReference::wgs84(), this);
    envelopeBuilder->setXMin(-88.1526);
    envelopeBuilder->setXMax(-88.1490);
    envelopeBuilder->setYMin(41.7694);
    envelopeBuilder->setYMax(41.7714);

    // Convert the envelope builder to an envelope object.
    Envelope offlineArea = envelopeBuilder->toEnvelope();

    // Create a graphic to visually represent the offline area.
    Graphic* box = new Graphic(offlineArea, new SimpleFillSymbol(
        SimpleFillSymbolStyle::Solid, Qt::transparent,
        new SimpleLineSymbol(SimpleLineSymbolStyle::Solid, Qt::red, 3, this), this), this);

    // Create a graphics overlay to hold the graphic.
    GraphicsOverlay* boxOverlay = new GraphicsOverlay(this);

    // Add the graphic to the graphics overlay.
    boxOverlay->graphics()->append(box);

    // Add the graphics overlay to the map view.
    m_mapView->graphicsOverlays()->append(boxOverlay);

    // Generate the offline map parameters.
    m_offlineMapTask->createDefaultGenerateOfflineMapParametersAsync(offlineArea).then(
        this,[this](const GenerateOfflineMapParameters& params)
    {

        // Generate the offline map. Store the .mmpk in the desired location.
        // IMPORTANT: Replace "ENTER_PATH_TO_MMPK_FILE" with the actual path where you want to save the .mmpk file.
        const QString outputPath = "ENTER_PATH_TO_MMPK_FILE/offlinemap.mmpk"; // Ex: "C:/mmpk_folder/offlinemap.mmpk"

        GenerateOfflineMapJob* generateJob = m_offlineMapTask->generateOfflineMap(params, outputPath);

        // Check if the generate job was created successfully.
        if (!generateJob)
            return;

        // Use connect to monitor job status for changes and return job status.
        connect(generateJob, &GenerateOfflineMapJob::statusChanged, this, [this, generateJob]()
                {
                    // Check the job status and handle accordingly.
                    if (generateJob->jobStatus() == JobStatus::Succeeded)
                    {
                        // The offline map has been successfully generated.
                        qDebug() << "generating offline map";

                        // Set the generated offline map to the map view.
                        m_mapView->setMap(generateJob->result()->offlineMap(this));

                        // Output any errors that occurred during the generation process.
                        qDebug() << (generateJob->error().isEmpty() ? "No errors" :
                         (generateJob->error().message() + generateJob->error().additionalMessage()));
                    }

                    // Handle other job statuses if necessary.
                    else if (generateJob->jobStatus() == JobStatus::Failed)
                    {
                        qWarning() << generateJob->error().message() << generateJob->error().additionalMessage();
                    }
                });

        // Use connect to monitor job progress changes and return progress return job progress.
        connect(generateJob, &GenerateOfflineMapJob::progressChanged, this, [generateJob]()
                {
                    qDebug() << "Job status:" << generateJob->progress() << "%";
                });

        // Start the generate offline map job.
        generateJob->start();
    });

}

Set developer credentials

For the final steps of this tutorial, click the tab below that corresponds to the authentication type (API key authentication or User authentication) that you chose when you completed the Display a map tutorial.

Be sure to also provide the same authentication (API key or user authentication Client ID/Redirect URL) that you used for the Display a map tutorial.

Set the API Key

In the project Display_a_map > Display_a_map > Source Files folder of Qt Creator, double click the main.cpp file to open it. Modify the code to set the accessToken variable using your API key access token. Then save the file.

main.cpp

    // The following methods grant an access token:

    // 1. User authentication: Grants a temporary access token associated with a user's ArcGIS account.
    // To generate a token, a user logs in to the app with an ArcGIS account that is part of an
    // organization in ArcGIS Online or ArcGIS Enterprise.

    // 2. API key authentication: Get a long-lived access token that gives your application access to
    // ArcGIS location services. Go to the tutorial at https://links.esri.com/create-an-api-key.
    // Copy the API Key access token.

    const QString accessToken = QString("");

    if (accessToken.isEmpty())
    {
        qWarning()
            << "Use of ArcGIS location services, such as the basemap styles service, requires"
            << "you to authenticate with an ArcGIS account or set the API Key property.";
    }
    else
    {
        ArcGISRuntimeEnvironment::setApiKey(accessToken);
    }

Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Set path to the Qt Toolkit in the project

In the project Display_a_map folder of Qt Creator, double-click the CMakeLists.txt file to open it. Locate the line that sets the ARCGIS_TOOLKIT_REPOSITORY variable and specify the path of the root directory of the ArcGIS Maps SDK for Qt Toolkit cloned repo that resides on your system (for example: C:/applications/arcgis-maps-sdk-toolkit-qt). If this is not correct the OAuth dialog will not appear for you to enter your user credentials. Then save the file.

CMakeLists.txt

# TODO: Replace the <path_to_toolkit_repo> with a valid location where the Qt Toolkit
# root directory resides on your system, example: C:/applications/arcgis-maps-sdk-toolkit-qt
# The code also sets the TOOLKIT_FOUND variable which is used by other parts of the tutorial.

set(ARCGIS_TOOLKIT_REPOSITORY "<path_to_toolkit_repo>")

Set developer credentials in the solution

In the project Display_a_map > Display_a_map > Source Files folder of Qt Creator, double-click the Display_a_map.cpp file to open it. Set your values for the REDIRECT_URL and the CLIENT_ID strings. Then save the file.

Display_a_map.cpp

{

#ifdef TOOLKIT_FOUND

    // Define the Redirect URL string obtained when creating the OAuth credentials.
    // TODO: You need to replace the "REDIRECT_URL" with your own valid string,
    // ex: "urn:ietf:wg:oauth:2.0:oob"

    const auto qStringRedirectUrl = QString{"REDIRECT_URL"};

    // Define the URL of the portal to authenticate with.
    const QUrl qUrlPortal = QUrl{"https://www.arcgis.com/"};

    // Define a unique identifier associated with an application registered with the
    // portal that assists with client/server OAuth authentication.
    // TODO: You need to replace the "CLIENT_ID" with your own valid string.

    const QString qStringClientId = QString{"CLIENT_ID"};

    // Create a new OAuth user configuration using: the Url to mapping web service, the Client ID
    // string, and the Redirect Url string.
    auto* oAuthUserConfiguration = new OAuthUserConfiguration(qUrlPortal, qStringClientId,
                                                              qStringRedirectUrl, this);

    // Call the Toolkit's OAuthUserConfigurationManager static `addConfiguration`
    // method to use the OAuth dialog. This will tell the Authenticator to use OAuth for the provided configuration.
    Toolkit::OAuthUserConfigurationManager::addConfiguration(oAuthUserConfiguration);
#endif // TOOLKIT_FOUND

Press Ctrl + R to run the app.

Initially, you should see the map of the stormwater network for Naperville, IL, USA, with a red outline as before. At the Application Output tab in Creator, the Job status percentage should increment up to 100%, and then you should see the offline map for the specified area of the stormwater network for Naperville, IL, USA. You should also be able to see the downloaded .mmpk file on the device hard drive for the outputPath variable you specified in the code. Remove your network connection and you will still be able to use the mouse to drag, scroll, and double-click the map view to explore this offline map.

Alternatively, you can download the tutorial solution, as follows.

Option 2: Download the solution

Click the Download solution link on this page under the Solution title and unzip the file to a location on your machine.

In Qt Creator, choose File > Open File or Project… from them menus. In the Open file dialog, navigate to the CMakeLists.txt file for the solution you unzipped and click the Open button.

The Configure Project window will appear for you to specify the Qt Kit to use to compile the project. Check on the Qt Kit called Desktop Qt 6.8.2 MSVC2022 64bit before clicking the Configure Project button at the bottom of the page.

Since the downloaded solution does not contain authentication credentials (API Key or User authentication), you must set up authentication to create the developer credentials and add them to the project.

In the project Display_a_map > Display_a_map > Source Files folder of Qt Creator, double-click the Display_a_map.cpp file to open it. You will need to store the resulting offline mobile map package (MMPK) in a location on your development machine. It is important that you specify the folder location that exists on the device and that it matches the code for the outputPath variable. The code line you need to modify is found in the generateMapByExtent() method.

Display_a_map.cpp

    // Generate the offline map parameters.
    m_offlineMapTask->createDefaultGenerateOfflineMapParametersAsync(offlineArea).then(
        this,[this](const GenerateOfflineMapParameters& params)
    {

        // Generate the offline map. Store the .mmpk in the desired location.
        // IMPORTANT: Replace "ENTER_PATH_TO_MMPK_FILE" with the actual path where you want to save the .mmpk file.
        const QString outputPath = "ENTER_PATH_TO_MMPK_FILE/offlinemap.mmpk"; // Ex: "C:/mmpk_folder/offlinemap.mmpk"

        GenerateOfflineMapJob* generateJob = m_offlineMapTask->generateOfflineMap(params, outputPath);

        // Check if the generate job was created successfully.
        if (!generateJob)
            return;

Be sure to also provide the same authentication (API key or user authentication Client ID/Redirect URL) that you used for the Display a map tutorial.

Set developer credentials in the solution

Set the API Key

main.cpp

    // The following methods grant an access token:

    // 1. User authentication: Grants a temporary access token associated with a user's ArcGIS account.
    // To generate a token, a user logs in to the app with an ArcGIS account that is part of an
    // organization in ArcGIS Online or ArcGIS Enterprise.

    // 2. API key authentication: Get a long-lived access token that gives your application access to
    // ArcGIS location services. Go to the tutorial at https://links.esri.com/create-an-api-key.
    // Copy the API Key access token.

    const QString accessToken = QString("");

    if (accessToken.isEmpty())
    {
        qWarning()
            << "Use of ArcGIS location services, such as the basemap styles service, requires"
            << "you to authenticate with an ArcGIS account or set the API Key property.";
    }
    else
    {
        ArcGISRuntimeEnvironment::setApiKey(accessToken);
    }

Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Set path to the Qt Toolkit in the project

CMakeLists.txt

# TODO: Replace the <path_to_toolkit_repo> with a valid location where the Qt Toolkit
# root directory resides on your system, example: C:/applications/arcgis-maps-sdk-toolkit-qt
# The code also sets the TOOLKIT_FOUND variable which is used by other parts of the tutorial.

set(ARCGIS_TOOLKIT_REPOSITORY "<path_to_toolkit_repo>")

Set developer credentials in the solution

Display_a_map.cpp

{

#ifdef TOOLKIT_FOUND

    // Define the Redirect URL string obtained when creating the OAuth credentials.
    // TODO: You need to replace the "REDIRECT_URL" with your own valid string,
    // ex: "urn:ietf:wg:oauth:2.0:oob"

    const auto qStringRedirectUrl = QString{"REDIRECT_URL"};

    // Define the URL of the portal to authenticate with.
    const QUrl qUrlPortal = QUrl{"https://www.arcgis.com/"};

    // Define a unique identifier associated with an application registered with the
    // portal that assists with client/server OAuth authentication.
    // TODO: You need to replace the "CLIENT_ID" with your own valid string.

    const QString qStringClientId = QString{"CLIENT_ID"};

    // Create a new OAuth user configuration using: the Url to mapping web service, the Client ID
    // string, and the Redirect Url string.
    auto* oAuthUserConfiguration = new OAuthUserConfiguration(qUrlPortal, qStringClientId,
                                                              qStringRedirectUrl, this);

    // Call the Toolkit's OAuthUserConfigurationManager static `addConfiguration`
    // method to use the OAuth dialog. This will tell the Authenticator to use OAuth for the provided configuration.
    Toolkit::OAuthUserConfigurationManager::addConfiguration(oAuthUserConfiguration);
#endif // TOOLKIT_FOUND

Run the app

Press Ctrl + R to run the app.

What’s next?

Learn how to use additional API features, ArcGIS location services, and ArcGIS tools in these tutorials:

Create a mobile map package

TutorialsCreate a mobile map package TutorialsDisplay a map from a mobile map package