Implement a widget provider in a win32 app (C++/WinRT)

This article walks you through creating a simple widget provider that implements the IWidgetProvider interface. The methods of this interface are invoked by the widget host to request the data that defines a widget or to let the widget provider respond to a user action on a widget. Widget providers can support a single widget or multiple widgets. In this example, we will define two different widgets. One widget is a mock weather widget that illustrates some of the formatting options provided by the Adaptive Cards framework. The second widget will demonstrate user actions and the custom widget state feature by maintaining a counter that is incremented whenever the user clicks on a button displayed on the widget.

A screenshot of a simple weather widget. The widget shows some weather-related graphics an data as well as some diagnostic text illustrating that the template for the medium size widget is being displayed.

A screenshot of a simple counting widget. The widget shows a string containing the numeric value to be incremented and a button labeled Increment, as well as some diagnostic text illustrating that the template for the small size widget is being displayed.

This sample code in this article is adapted from the Windows App SDK Widgets Sample. To implement a widget provider using C#, see Implement a widget provider in a win32 app (C#).

Prerequisites

  • Your device must have developer mode enabled. For more information see Enable your device for development.
  • Visual Studio 2022 or later with the Universal Windows Platform development workload. Make sure to add the component for C++ (v143) from the optional dropdown.

Create a new C++/WinRT win32 console app

In Visual Studio, create a new project. In the Create a new project dialog, set the language filter to "C++" and the platform filter to Windows, then select the Windows Console Application (C++/WinRT) project template. Name the new project "ExampleWidgetProvider". When prompted, set the target Windows version for the app to version 1809 or later.

Add references to the Windows App SDK and Windows Implementation Library NuGet packages

This sample uses the latest stable Windows App SDK NuGet package. In Solution Explorer, right-click References and select Manage NuGet packages.... In the NuGet package manager, select the Browse tab and search for "Microsoft.WindowsAppSDK". Select the latest stable version in the Version drop-down and then click Install.

This sample also uses the Windows Implementation Library NuGet package. In Solution Explorer, right-click References and select Manage NuGet packages.... In the NuGet package manager, select the Browse tab and search for "Microsoft.Windows.ImplementationLibrary". Select the latest version in the Version drop-down and then click Install.

In the precompiled header file, pch.h, add the following include directives.

//pch.h 
#pragma once
#include <wil/cppwinrt.h>
#include <wil/resource.h>
...
#include <winrt/Microsoft.Windows.Widgets.Providers.h>

Note

You must include the wil/cppwinrt.h header first, before any WinRT headers.

In order to handle shutting down the widget provider app correctly, we need to a custom implementation of winrt::get_module_lock. We pre-declare the SignalLocalServerShutdown method which will be defined in our main.cpp file and will set an event that signals the app to exit. Add the following code to your pch.h file, just below the #pragma once directive, before the other includes.

//pch.h
#include <stdint.h>
#include <combaseapi.h>

// In .exe local servers the class object must not contribute to the module ref count, and use
// winrt::no_module_lock, the other objects must and this is the hook into the C++ WinRT ref counting system
// that enables this.
void SignalLocalServerShutdown();

namespace winrt
{
    inline auto get_module_lock() noexcept
    {
        struct service_lock
        {
            uint32_t operator++() noexcept
            {
                return ::CoAddRefServerProcess();
            }

            uint32_t operator--() noexcept
            {
                const auto ref = ::CoReleaseServerProcess();

                if (ref == 0)
                {
                    SignalLocalServerShutdown();
                }
                return ref;
            }
        };

        return service_lock{};
    }
}


#define WINRT_CUSTOM_MODULE_LOCK

Add a WidgetProvider class to handle widget operations

In Visual Studio, right-click the ExampleWidgetProvider project in Solution Explorer and select Add->Class. In the Add class dialog, name the class "WidgetProvider" and click Add.

Declare a class that implements the IWidgetProvider interface

The IWidgetProvider interface defines methods that the widget host will invoke to initiate operations with the widget provider. Replace the empty class definition in the WidgetProvider.h file with the following code. This code declares a structure that implements the IWidgetProvider interface and declares prototypes for the interface methods.

// WidgetProvider.h
struct WidgetProvider : winrt::implements<WidgetProvider, winrt::Microsoft::Windows::Widgets::Providers::IWidgetProvider>
{
    WidgetProvider();

    /* IWidgetProvider required functions that need to be implemented */
    void CreateWidget(winrt::Microsoft::Windows::Widgets::Providers::WidgetContext WidgetContext);
    void DeleteWidget(winrt::hstring const& widgetId, winrt::hstring const& customState);
    void OnActionInvoked(winrt::Microsoft::Windows::Widgets::Providers::WidgetActionInvokedArgs actionInvokedArgs);
    void OnWidgetContextChanged(winrt::Microsoft::Windows::Widgets::Providers::WidgetContextChangedArgs contextChangedArgs);
    void Activate(winrt::Microsoft::Windows::Widgets::Providers::WidgetContext widgetContext);
    void Deactivate(winrt::hstring widgetId);
    /* IWidgetProvider required functions that need to be implemented */

    
};

Also, add a private method, UpdateWidget, which is a helper method that will send updates from our provider to the widget host.

// WidgetProvider.h
private: 

void UpdateWidget(CompactWidgetInfo const& localWidgetInfo);

Prepare to track enabled widgets

A widget provider can support a single widget or multiple widgets. Whenever the widget host initiates an operation with the widget provider, it passes an ID to identify the widget associated with the operation. Each widget also has an associated name and a state value that can be used to store custom data. For this example, we'll declare a simple helper structure to store the ID, name, and data for each pinned widget. Widgets also can be in an active state, which is discussed in the Activate and Deactivate section below, and we will track this state for each widget with a boolean value. Add the following definition to the WidgetProvider.h file, above the WidgetProvider struct declaration.

// WidgetProvider.h
struct CompactWidgetInfo
{
    winrt::hstring widgetId;
    winrt::hstring widgetName;
    int customState = 0;
    bool isActive = false;
};

Inside the WidgetProvider declaration in WidgetProvider.h, add a member for the map that will maintain the list of enabled widgets, using the widget ID as the key for each entry.

// WidgetProvider.h
struct WidgetProvider : winrt::implements<WidgetProvider, winrt::Microsoft::Windows::Widgets::Providers::IWidgetProvider>
{
...
    private:
        ...
        static std::unordered_map<winrt::hstring, CompactWidgetInfo> RunningWidgets;

        

Declare widget template JSON strings

This example will declare some static strings to define the JSON templates for each widget. For convenience, these templates are stored in the local variables declared outside of the WidgetProvider class definition. If you need a general storage for the templates - they can be included as part of the application package: Accessing Package Files. For information on creating the widget template JSON document, see Create a widget template with the Adaptive Card Designer.

// WidgetProvider.h
const std::string weatherWidgetTemplate = R"(
{
    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
    "type": "AdaptiveCard",
    "version": "1.0",
    "speak": "<s>The forecast for Seattle January 20 is mostly clear with a High of 51 degrees and Low of 40 degrees</s>",
    "backgroundImage": "https://messagecardplayground.azurewebsites.net/assets/Mostly%20Cloudy-Background.jpg",
    "body": [
        {
            "type": "TextBlock",
            "text": "Redmond, WA",
            "size": "large",
            "isSubtle": true,
            "wrap": true
        },
        {
            "type": "TextBlock",
            "text": "Mon, Nov 4, 2019 6:21 PM",
            "spacing": "none",
            "wrap": true
        },
        {
            "type": "ColumnSet",
            "columns": [
                {
                    "type": "Column",
                    "width": "auto",
                    "items": [
                        {
                            "type": "Image",
                            "url": "https://messagecardplayground.azurewebsites.net/assets/Mostly%20Cloudy-Square.png",
                            "size": "small",
                            "altText": "Mostly cloudy weather"
                        }
                    ]
                },
                {
                    "type": "Column",
                    "width": "auto",
                    "items": [
                        {
                            "type": "TextBlock",
                            "text": "46",
                            "size": "extraLarge",
                            "spacing": "none",
                            "wrap": true
                        }
                    ]
                },
                {
                    "type": "Column",
                    "width": "stretch",
                    "items": [
                        {
                            "type": "TextBlock",
                            "text": "°F",
                            "weight": "bolder",
                            "spacing": "small",
                            "wrap": true
                        }
                    ]
                },
                {
                    "type": "Column",
                    "width": "stretch",
                    "items": [
                        {
                            "type": "TextBlock",
                            "text": "Hi 50",
                            "horizontalAlignment": "left",
                            "wrap": true
                        },
                        {
                            "type": "TextBlock",
                            "text": "Lo 41",
                            "horizontalAlignment": "left",
                            "spacing": "none",
                            "wrap": true
                        }
                    ]
                }
            ]
        }
    ]
})";

const std::string countWidgetTemplate = R"(
{                                                                     
    "type": "AdaptiveCard",                                         
    "body": [                                                         
        {                                                               
            "type": "TextBlock",                                    
            "text": "You have clicked the button ${count} times"    
        },
        {
             "text":"Rendering Only if Medium",
             "type":"TextBlock",
             "$when":"${$host.widgetSize==\"medium\"}"
        },
        {
             "text":"Rendering Only if Small",
             "type":"TextBlock",
             "$when":"${$host.widgetSize==\"small\"}"
        },
        {
         "text":"Rendering Only if Large",
         "type":"TextBlock",
         "$when":"${$host.widgetSize==\"large\"}"
        }                                                                    
    ],                                                                  
    "actions": [                                                      
        {                                                               
            "type": "Action.Execute",                               
            "title": "Increment",                                   
            "verb": "inc"                                           
        }                                                               
    ],                                                                  
    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
    "version": "1.5"                                                
})";

Implement the IWidgetProvider methods

In the next few sections, we'll implement the methods of the IWidgetProvider interface. The helper method UpdateWidget that is called in several of these method implementations will be shown later in this article. Before diving into the interface methods, add the following lines to WidgetProvider.cpp, after the include directives, to pull the widget provider APIs into the winrt namespace and allow access to the map we declared in the previous step.

Note

Objects passed into the callback methods of the IWidgetProvider interface are only guaranteed to be valid within the callback. You should not store references to these objects because their behavior outside of the context of the callback is undefined.

// WidgetProvider.cpp
namespace winrt
{
    using namespace Microsoft::Windows::Widgets::Providers;
}

std::unordered_map<winrt::hstring, CompactWidgetInfo> WidgetProvider::RunningWidgets{};

CreateWidget

The widget host calls CreateWidget when the user has pinned one of your app's widgets in the widget host. First, this method gets the ID and name of the associated widget and adds a new instance of our helper structure, CompactWidgetInfo, to the collection of enabled widgets. Next, we send the initial template and data for the widget, which is encapsulated in the UpdateWidget helper method.

// WidgetProvider.cpp
void WidgetProvider::CreateWidget(winrt::WidgetContext widgetContext)
{
    auto widgetId = widgetContext.Id();
    auto widgetName = widgetContext.DefinitionId();
    CompactWidgetInfo runningWidgetInfo{ widgetId, widgetName };
    RunningWidgets[widgetId] = runningWidgetInfo;
    
    // Update the widget
    UpdateWidget(runningWidgetInfo);
}

DeleteWidget

The widget host calls DeleteWidget when the user has unpinned one of your app's widgets from the widget host. When this occurs, we will remove the associated widget from our list of enabled widgets so that we don't send any further updates for that widget.

// WidgetProvider.cpp
void WidgetProvider::DeleteWidget(winrt::hstring const& widgetId, winrt::hstring const& customState)
{
    RunningWidgets.erase(widgetId);
}

OnActionInvoked

The widget host calls OnActionInvoked when the user interacts with an action you defined in your widget template. For the counter widget used in this example, an action was declared with a verb value of "inc" in the JSON template for the widget. The widget provider code will use this verb value to determine what action to take in response to the user interaction.

...
    "actions": [                                                      
        {                                                               
            "type": "Action.Execute",                               
            "title": "Increment",                                   
            "verb": "inc"                                           
        }                                                               
    ], 
...

In the OnActionInvoked method, get the verb value by checking the Verb property of the WidgetActionInvokedArgs passed into the method. If the verb is "inc", then we know we are going to increment the count in the custom state for the widget. From the WidgetActionInvokedArgs, get the WidgetContext object and then the WidgetId to get the ID for the widget that is being updated. Find the entry in our enabled widgets map with the specified ID and then update the custom state value that is used to store the number of increments. Finally, update the widget content with the new value with the UpdateWidget helper function.

// WidgetProvider.cpp
void WidgetProvider::OnActionInvoked(winrt::WidgetActionInvokedArgs actionInvokedArgs)
{
    auto verb = actionInvokedArgs.Verb();
    if (verb == L"inc")
    {
        auto widgetId = actionInvokedArgs.WidgetContext().Id();
        // If you need to use some data that was passed in after
        // Action was invoked, you can get it from the args:
        auto data = actionInvokedArgs.Data();
        if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
        {
            auto& localWidgetInfo = iter->second;
            // Increment the count
            localWidgetInfo.customState++;
            UpdateWidget(localWidgetInfo);
        }
    }
}

For information about the Action.Execute syntax for Adaptive Cards, see Action.Execute. For guidance about designing interaction for widgets, see Widget interaction design guidance

OnWidgetContextChanged

In the current release, OnWidgetContextChanged is only called when the user changes the size of a pinned widget. You can choose to return a different JSON template/data to the widget host depending on what size is requested. You can also design the template JSON to support all the available sizes using conditional rendering based on the value of host.widgetSize. If you don't need to send a new template or data to account for the size change, you can use the OnWidgetContextChanged for telemetry purposes.

// WidgetProvider.cpp
void WidgetProvider::OnWidgetContextChanged(winrt::WidgetContextChangedArgs contextChangedArgs)
{
    auto widgetContext = contextChangedArgs.WidgetContext();
    auto widgetId = widgetContext.Id();
    auto widgetSize = widgetContext.Size();
    if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
    {
        auto localWidgetInfo = iter->second;

        UpdateWidget(localWidgetInfo);
    }
}
    

Activate and Deactivate

The Activate method is called to notify the widget provider that the widget host is currently interested in receiving updated content from the provider. For example, it could mean that the user is currently actively viewing the widget host. The Deactivate method is called to notify the widget provider that the widget host is no longer requesting content updates. These two methods define a window in which the widget host is most interested in showing the most up-to-date content. Widget providers can send updates to the widget at any time, such as in response to a push notification, but as with any background task, it's important to balance providing up-to-date content with resource concerns like battery life.

Activate and Deactivate are called on a per-widget basis. This example tracks the active status of each widget in the CompactWidgetInfo helper struct. In the Activate method, we call the UpdateWidget helper method to update our widget. Note that the time window between Activate and Deactivate may be small, so it's recommended that you try to make your widget update code path as quick as possible.

void WidgetProvider::Activate(winrt::Microsoft::Windows::Widgets::Providers::WidgetContext widgetContext)
{
    auto widgetId = widgetContext.Id();

    if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
    {
        auto& localWidgetInfo = iter->second;
        localWidgetInfo.isActive = true;

        UpdateWidget(localWidgetInfo);
    }
}

void WidgetProvider::Deactivate(winrt::hstring widgetId)
{
    if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
    {
        auto& localWidgetInfo = iter->second;
        localWidgetInfo.isActive = false;
    }
}

Update a widget

Define the UpdateWidget helper method to update an enabled widget. In this example, we check the name of the widget in the CompactWidgetInfo helper struct passed into the method, and then set the appropriate template and data JSON based on which widget is being updated. A WidgetUpdateRequestOptions is initialized with the template, data, and custom state for the widget being updated. Call WidgetManager::GetDefault to get an instance of the WidgetManager class and then call UpdateWidget to send the updated widget data to the widget host.

// WidgetProvider.cpp
void WidgetProvider::UpdateWidget(CompactWidgetInfo const& localWidgetInfo)
{
    winrt::WidgetUpdateRequestOptions updateOptions{ localWidgetInfo.widgetId };

    winrt::hstring templateJson;
    if (localWidgetInfo.widgetName == L"Weather_Widget")
    {
        templateJson = winrt::to_hstring(weatherWidgetTemplate);
    }
    else if (localWidgetInfo.widgetName == L"Counting_Widget")
    {
        templateJson = winrt::to_hstring(countWidgetTemplate);
    }

    winrt::hstring dataJson;
    if (localWidgetInfo.widgetName == L"Weather_Widget")
    {
        dataJson = L"{}";
    }
    else if (localWidgetInfo.widgetName == L"Counting_Widget")
    {
        dataJson = L"{ \"count\": " + winrt::to_hstring(localWidgetInfo.customState) + L" }";
    }

    updateOptions.Template(templateJson);
    updateOptions.Data(dataJson);
    // You can store some custom state in the widget service that you will be able to query at any time.
    updateOptions.CustomState(winrt::to_hstring(localWidgetInfo.customState));
    winrt::WidgetManager::GetDefault().UpdateWidget(updateOptions);
}

Initialize the list of enabled widgets on startup

When our widget provider is first initialized, it's a good idea to ask WidgetManager if there are any running widgets that our provider is currently serving. It will help to recover the app to the previous state in case of the computer restart or the provider crash. Call WidgetManager::GetDefault to get the default widget manager instance for the app. Then call GetWidgetInfos, which returns an array of WidgetInfo objects. Copy the widget IDs, names, and custom state into the helper struct CompactWidgetInfo and save it to the RunningWidgets member variable. Paste the following code into the constructor for the WidgetProvider class.

// WidgetProvider.cpp
WidgetProvider::WidgetProvider()
{
    auto runningWidgets = winrt::WidgetManager::GetDefault().GetWidgetInfos();
    for (auto widgetInfo : runningWidgets )
    {
        auto widgetContext = widgetInfo.WidgetContext();
        auto widgetId = widgetContext.Id();
        auto widgetName = widgetContext.DefinitionId();
        auto customState = widgetInfo.CustomState();
        if (RunningWidgets.find(widgetId) == RunningWidgets.end())
        {
            CompactWidgetInfo runningWidgetInfo{ widgetId, widgetName };
            try
            {
                // If we had any save state (in this case we might have some state saved for Counting widget)
                // convert string to required type if needed.
                int count = std::stoi(winrt::to_string(customState));
                runningWidgetInfo.customState = count;
            }
            catch (...)
            {

            }
            RunningWidgets[widgetId] = runningWidgetInfo;
        }
    }
}

Register a class factory that will instantiate WidgetProvider on request

Add the header that defines the WidgetProvider class to the includes at the top of your app's main.cpp file. We will also be including mutex here.

// main.cpp
...
#include "WidgetProvider.h"
#include <mutex>

Declare the event that will trigger our app to exit and the SignalLocalServerShutdown function that will set the event. Paste the following code in main.cpp.

// main.cpp
wil::unique_event g_shudownEvent(wil::EventOptions::None);

void SignalLocalServerShutdown()
{
    g_shudownEvent.SetEvent();
}

Next, you will need to create a CLSID that will be used to identify your widget provider for COM activation. Generate a GUID in Visual Studio by going to Tools->Create GUID. Select the option "static const GUID =" and click Copy and then paste that into main.cpp. Update the GUID definition with the following C++/WinRT syntax, setting the GUID variable name widget_provider_clsid. Leave the commented version of the GUID because you will need this format later, when packaging your app.

// main.cpp
...
// {80F4CB41-5758-4493-9180-4FB8D480E3F5}
static constexpr GUID widget_provider_clsid
{
    0x80f4cb41, 0x5758, 0x4493, { 0x91, 0x80, 0x4f, 0xb8, 0xd4, 0x80, 0xe3, 0xf5 }
};

Add the following class factory definition to main.cpp. This is mostly boilerplate code that is not specific to widget provider implementations. Note that CoWaitForMultipleObjects waits for our shutdown event to be triggered before the app exits.

// main.cpp
template <typename T>
struct SingletonClassFactory : winrt::implements<SingletonClassFactory<T>, IClassFactory>
{
    STDMETHODIMP CreateInstance(
        ::IUnknown* outer,
        GUID const& iid,
        void** result) noexcept final
    {
        *result = nullptr;

        std::unique_lock lock(mutex);

        if (outer)
        {
            return CLASS_E_NOAGGREGATION;
        }

        if (!instance)
        {
            instance = winrt::make<WidgetProvider>();
        }

        return instance.as(iid, result);
    }

    STDMETHODIMP LockServer(BOOL) noexcept final
    {
        return S_OK;
    }

private:
    T instance{ nullptr };
    std::mutex mutex;
};

int main()
{
    winrt::init_apartment();
    wil::unique_com_class_object_cookie widgetProviderFactory;
    auto factory = winrt::make<SingletonClassFactory<winrt::Microsoft::Windows::Widgets::Providers::IWidgetProvider>>();

    winrt::check_hresult(CoRegisterClassObject(
        widget_provider_clsid,
        factory.get(),
        CLSCTX_LOCAL_SERVER,
        REGCLS_MULTIPLEUSE,
        widgetProviderFactory.put()));

    DWORD index{};
    HANDLE events[] = { g_shudownEvent.get() };
    winrt::check_hresult(CoWaitForMultipleObjects(CWMO_DISPATCH_CALLS | CWMO_DISPATCH_WINDOW_MESSAGES,
        INFINITE,
        static_cast<ULONG>(std::size(events)), events, &index));

    return 0;
}

Package your widget provider app

In the current release, only packaged apps can be registered as widget providers. The following steps will take you through the process of packaging your app and updating the app manifest to register your app with the OS as a widget provider.

Create an MSIX packaging project

In Solution Explorer, right-click your solution and select Add->New Project.... In the Add a new project dialog, select the "Windows Application Packaging Project" template and click Next. Set the project name to "ExampleWidgetProviderPackage" and click Create. When prompted, set the target version to version 1809 or later and click OK. Next, right-click the ExampleWidgetProviderPackage project and select Add->Project reference. Select the ExampleWidgetProvider project and click OK.

Add Windows App SDK package reference to the packaging project

You need to add a reference to the Windows App SDK nuget package to the MSIX packaging project. In Solution Explorer, double-click the ExampleWidgetProviderPackage project to open the ExampleWidgetProviderPackage.wapproj file. Add the following xml inside the Project element.

<!--ExampleWidgetProviderPackage.wapproj-->
<ItemGroup>
    <PackageReference Include="Microsoft.WindowsAppSDK" Version="1.2.221116.1">
        <IncludeAssets>build</IncludeAssets>
    </PackageReference>  
</ItemGroup>

Note

Make sure the Version specified in the PackageReference element matches the latest stable version you referenced in the previous step.

If the correct version of the Windows App SDK is already installed on the computer and you don't want to bundle the SDK runtime in your package, you can specify the package dependency in the Package.appxmanifest file for the ExampleWidgetProviderPackage project.

<!--Package.appxmanifest-->
...
<Dependencies>
...
    <PackageDependency Name="Microsoft.WindowsAppRuntime.1.2-preview2" MinVersion="2000.638.7.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
...
</Dependencies>
...

Update the package manifest

In Solution Explorer right-click the Package.appxmanifest file and select View Code to open the manifest xml file. Next you need to add some namespace declarations for the app package extensions we will be using. Add the following namespace definitions to the top-level Package element.

<!-- Package.appmanifest -->
<Package
  ...
  xmlns:uap3="http://schemas.microsoft.com/appx/manifest/uap/windows10/3"
  xmlns:com="http://schemas.microsoft.com/appx/manifest/com/windows10"

Inside the Application element, create a new empty element named Extensions. Make sure this comes after the closing tag for uap:VisualElements.

<!-- Package.appxmanifest -->
<Application>
...
    <Extensions>

    </Extensions>
</Application>

The first extension we need to add is the ComServer extension. This registers the entry point of the executable with the OS. This extension is the packaged app equivalent of registering a COM server by setting a registry key, and is not specific to widget providers.Add the following com:Extension element as a child of the Extensions element. Change the GUID in the Id attribute of the com:Class element to the GUID you generated in a previous step.

<!-- Package.appxmanifest -->
<Extensions>
    <com:Extension Category="windows.comServer">
        <com:ComServer>
            <com:ExeServer Executable="ExampleWidgetProvider\ExampleWidgetProvider.exe" DisplayName="ExampleWidgetProvider">
                <com:Class Id="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" DisplayName="ExampleWidgetProvider" />
            </com:ExeServer>
        </com:ComServer>
    </com:Extension>
</Extensions>

Next, add the extension that registers the app as a widget provider. Paste the uap3:Extension element in the following code snippet, as a child of the Extensions element. Be sure to replace the ClassId attribute of the COM element with the GUID you used in previous steps.

<!-- Package.appxmanifest -->
<Extensions>
    ...
    <uap3:Extension Category="windows.appExtension">
        <uap3:AppExtension Name="com.microsoft.windows.widgets" DisplayName="WidgetTestApp" Id="ContosoWidgetApp" PublicFolder="Public">
            <uap3:Properties>
                <WidgetProvider>
                    <ProviderIcons>
                        <Icon Path="Images\StoreLogo.png" />
                    </ProviderIcons>
                    <Activation>
                        <!-- Apps exports COM interface which implements IWidgetProvider -->
                        <CreateInstance ClassId="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" />
                    </Activation>

                    <TrustedPackageFamilyNames>
                        <TrustedPackageFamilyName>Microsoft.MicrosoftEdge.Stable_8wekyb3d8bbwe</TrustedPackageFamilyName>
                    </TrustedPackageFamilyNames>

                    <Definitions>
                        <Definition Id="Weather_Widget"
                            DisplayName="Weather Widget"
                            Description="Weather Widget Description"
                            AllowMultiple="true">
                            <Capabilities>
                                <Capability>
                                    <Size Name="small" />
                                </Capability>
                                <Capability>
                                    <Size Name="medium" />
                                </Capability>
                                <Capability>
                                    <Size Name="large" />
                                </Capability>
                            </Capabilities>
                            <ThemeResources>
                                <Icons>
                                    <Icon Path="ProviderAssets\Weather_Icon.png" />
                                </Icons>
                                <Screenshots>
                                    <Screenshot Path="ProviderAssets\Weather_Screenshot.png" DisplayAltText="For accessibility" />
                                </Screenshots>
                                <!-- DarkMode and LightMode are optional -->
                                <DarkMode />
                                <LightMode />
                            </ThemeResources>
                        </Definition>
                        <Definition Id="Counting_Widget"
                                DisplayName="Microsoft Counting Widget"
                                Description="Couting Widget Description">
                            <Capabilities>
                                <Capability>
                                    <Size Name="small" />
                                </Capability>
                            </Capabilities>
                            <ThemeResources>
                                <Icons>
                                    <Icon Path="ProviderAssets\Counting_Icon.png" />
                                </Icons>
                                <Screenshots>
                                    <Screenshot Path="ProviderAssets\Counting_Screenshot.png" DisplayAltText="For accessibility" />
                                </Screenshots>
                                <!-- DarkMode and LightMode are optional -->
                                <DarkMode>

                                </DarkMode>
                                <LightMode />
                            </ThemeResources>
                        </Definition>
                    </Definitions>
                </WidgetProvider>
            </uap3:Properties>
        </uap3:AppExtension>
    </uap3:Extension>
</Extensions>

For detailed descriptions and format information for all of these elements, see Widget provider package manifest XML format.

Add icons and other images to your packaging project

In Solution Explorer, right-click your ExampleWidgetProviderPackage and select Add->New Folder. Name this folder ProviderAssets as this is what was used in the Package.appxmanifest from the previous step. This is where we will store our Icons and Screenshots for our widgets. Once you add your desired Icons and Screenshots, make sure the image names match what comes after Path=ProviderAssets\ in your Package.appxmanifest or the widgets will not show up in the widget host.

For information about the design requirements for screenshot images and the naming conventions for localized screenshots, see Integrate with the widget picker.

Testing your widget provider

Make sure you have selected the architecture that matches your development machine from the Solution Platforms drop-down, for example "x64". In Solution Explorer, right-click your solution and select Build Solution. Once this is done, right-click your ExampleWidgetProviderPackage and select Deploy. In the current release, the only supported widget host is the Widgets Board. To see the widgets you will need to open the Widgets Board and select Add widgets in the top right. Scroll to the bottom of the available widgets and you should see the mock Weather Widget and Microsoft Counting Widget that were created in this tutorial. Click on the widgets to pin them to your widgets board and test their functionality.

Debugging your widget provider

After you have pinned your widgets, the Widget Platform will start your widget provider application in order to receive and send relevant information about the widget. To debug the running widget you can either attach a debugger to the running widget provider application or you can set up Visual Studio to automatically start debugging the widget provider process once it's started.

In order to attach to the running process:

  1. In Visual Studio click Debug -> Attach to process.
  2. Filter the processes and find your desired widget provider application.
  3. Attach the debugger.

In order to automatically attach the debugger to the process when it's initially started:

  1. In Visual Studio click Debug -> Other Debug Targets -> Debug Installed App Package.
  2. Filter the packages and find your desired widget provider package.
  3. Select it and check the box that says Do not launch, but debug my code when it starts.
  4. Click Attach.

Convert your console app to a Windows app

To convert the console app created in this walkthrough to a Windows app:

  1. Right-click on the ExampleWidgetProvider project in Solution Explorer and select Properties. Navigate to Linker -> System and change SubSystem from "Console" to "Windows". This can also be done by adding <SubSystem>Windows</SubSystem> to the <Link>..</Link> section of the .vcxproj.
  2. In main.cpp, change int main() to int WINAPI wWinMain(_In_ HINSTANCE /*hInstance*/, _In_opt_ HINSTANCE /*hPrevInstance*/, _In_ PWSTR pCmdLine, _In_ int /*nCmdShow*/).

A screenshot showing the C++ widget provider project properties with the output type set to Windows Application

Publishing your widget

After you have developed and tested your widget you can publish your app on the Microsoft Store in order for users to install your widgets on their devices. For step by step guidance for publishing an app, see Publish your app in the Microsoft Store.

The widgets Store Collection

After your app has been published on the Microsoft Store, you can request for your app to be included in the widgets Store Collection that helps users discover apps that feature Windows Widgets. To submit your request, see Submit your Widget information for addition to the Store Collection.

Screenshot of the Microsoft Store showing the widgets collection that allows users to discover apps that feature Windows Widgets.

Implementing widget customization

Starting with Windows App SDK 1.4, widgets can support user customization. When this feature is implemented, a Customize widget option is added to the ellipsis menu above the Unpin widget option.

A screenshot showing a widget with the customization dialog displayed.

The following steps summarize the process for widget customization.

  1. In normal operation, the widget provider responds to requests from the widget host with the visual and data JSON templates for the regular widget experience.
  2. The user clicks the Customize widget button in the ellipsis menu.
  3. The widget raises the OnCustomizationRequested event on the widget provider to indicate that the user has requested the widget customization experience.
  4. The widget provider sets an internal flag to indicate that the widget is in customization mode. While in customization mode, the widget provider sends the JSON templates for the widget customization UI instead of the regular widget UI.
  5. While in customization mode, the widget provider receives OnActionInvoked events as the user interacts with the customization UI and adjusts its internal configuration and behavior based on the user's actions.
  6. When the action associated with the OnActionInvoked event is the app-defined "exit customization" action, the widget provider resets it's internal flag to indicate that it is no longer in customization mode and resumes sending the visual and data JSON templates for the regular widget experience, reflecting the changes requested during customization.
  7. The widget provider persists the customization options to disk or the cloud so that the changes are preserved between invocations of the widget provider.

Note

There is a known bug with the Windows Widget Board, for widgets built using the Windows App SDK, that causes the ellipsis menu to become unresponsive after the customization card is shown.

In typical Widget customization scenarios, the user will choose what data is displayed on the widget or adjust visual presentation of the widget. For simplicity, the example in this section will add customization behavior that allows the user to reset the counter of the counting widget implemented in the previous steps.

Note

Widget customization is only supported in Windows App SDK 1.4 and later. Make sure you update the references in your project to the latest version of the Nuget package.

Update the package manifest to declare customization support

To let the widget host know that the widget supports customization, add the attribute IsCustomizable to the Definition eleent for the widget and set it to true.

...
<Definition Id="Counting_Widget"
    DisplayName="Microsoft Counting Widget"
    Description="CONFIG counting widget description"
    IsCustomizable="true">
...

Update WidgetProvider.h

To add customization support to the widget that was created in the previous steps in this article, we will need to update the header file for our widget provider, WidgetProvider.h.

First, update the CompactWidgetInfo definition. This helper struct helps us track the current state of our active widgets. Add the inCustomization field, which will be used to track when the widget host is expecting us to send our customization json template rather than the regular widget template.

// WidgetProvider.h
struct CompactWidgetInfo
{
    winrt::hstring widgetId;
    winrt::hstring widgetName;
    int customState = 0;
    bool isActive = false;
    bool inCustomization = false;
};

Update the WidgetProvider declaration to implement the IWidgetProvider2 interface.

// WidgetProvider.h

struct WidgetProvider : winrt::implements<WidgetProvider, winrt::Microsoft::Windows::Widgets::Providers::IWidgetProvider, winrt::Microsoft::Windows::Widgets::Providers::IWidgetProvider2>

Add a declaration for the OnCustomizationRequested callback of the IWidgetProvider2 interface.

// WidgetProvider.h

void OnCustomizationRequested(winrt::Microsoft::Windows::Widgets::Providers::WidgetCustomizationRequestedArgs args);

Finally, declare a string variable that defines the JSON template for the widget customization UI. For this example, we have a "Reset counter" button and an "Exit customization" button that will signal our provider to return to regular widget behavior.

// WidgetProvider.h
const std::string countWidgetCustomizationTemplate = R"(
{
    "type": "AdaptiveCard",
    "actions" : [
        {
            "type": "Action.Execute",
            "title" : "Reset counter",
            "verb": "reset"
            },
            {
            "type": "Action.Execute",
            "title": "Exit customization",
            "verb": "exitCustomization"
            }
    ],
    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
    "version": "1.5"
})";

Update WidgetProvider.cpp

Now update the WidgetProvider.cpp file to implement the widget customization behavior. This method uses the same pattern as the other callbacks we have used. We get the ID for the widget to be customized from the WidgetContext and find the CompactWidgetInfo helper struct associated with that widget and set the inCustomization field to true.

//WidgetProvider.cpp
void WidgetProvider::OnCustomizationRequested(winrt::WidgetCustomizationRequestedArgs args)
{
    auto widgetId = args.WidgetContext().Id();

    if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
    {
        auto& localWidgetInfo = iter->second;
        localWidgetInfo.inCustomization = true;

        UpdateWidget(localWidgetInfo);
    }
}

Next, we'll update our UpdateWidget helper method that sends our data and visual JSON templates to the widget host. When we are updating the counting widget, we send either the regular widget template or the customization template depending on the value of the inCustomization field. For brevity, code not relevant to customization is omitted in this code snippet.

//WidgetProvider.cpp
void WidgetProvider::UpdateWidget(CompactWidgetInfo const& localWidgetInfo)
{
    ...
    else if (localWidgetInfo.widgetName == L"Counting_Widget")
    {
        if (!localWidgetInfo.inCustomization)
        {
            std::wcout << L" - not in customization " << std::endl;
            templateJson = winrt::to_hstring(countWidgetTemplate);
		}
        else
        {
            std::wcout << L" - in customization " << std::endl;
            templateJson = winrt::to_hstring(countWidgetCustomizationTemplate);
		}
    }
    ...
    
    updateOptions.Template(templateJson);
    updateOptions.Data(dataJson);
    // !!  You can store some custom state in the widget service that you will be able to query at any time.
    updateOptions.CustomState(winrt::to_hstring(localWidgetInfo.customState));
    winrt::WidgetManager::GetDefault().UpdateWidget(updateOptions);
}

When users interact with inputs in our customization template, it calls the same OnActionInvoked handler as when the user interacts with the regular widget experience. To support customization, we look for the verbs "reset" and "exitCustomization" from our customization JSON template. If the action is for the "Reset counter" button, we reset the counter held in the customState field of our helper struct to 0. If the action is for the "Exit customization" button, we set the inCustomization field to false so that when we call UpdateWidget, our helper method will send the regular JSON templates and not the customization template.

//WidgetProvider.cpp
void WidgetProvider::OnActionInvoked(winrt::WidgetActionInvokedArgs actionInvokedArgs)
{
    auto verb = actionInvokedArgs.Verb();
    if (verb == L"inc")
    {
        auto widgetId = actionInvokedArgs.WidgetContext().Id();
        // If you need to use some data that was passed in after
        // Action was invoked, you can get it from the args:
        auto data = actionInvokedArgs.Data();
        if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
        {
            auto& localWidgetInfo = iter->second;
            // Increment the count
            localWidgetInfo.customState++;
            UpdateWidget(localWidgetInfo);
        }
    }
    else if (verb == L"reset") 
    {
        auto widgetId = actionInvokedArgs.WidgetContext().Id();
        auto data = actionInvokedArgs.Data();
        if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
        {
            auto& localWidgetInfo = iter->second;
            // Reset the count
            localWidgetInfo.customState = 0;
            localWidgetInfo.inCustomization = false;
            UpdateWidget(localWidgetInfo);
        }
    }
    else if (verb == L"exitCustomization")
    {
        auto widgetId = actionInvokedArgs.WidgetContext().Id();
        // If you need to use some data that was passed in after
        // Action was invoked, you can get it from the args:
        auto data = actionInvokedArgs.Data();
        if (const auto iter = RunningWidgets.find(widgetId); iter != RunningWidgets.end())
        {
            auto& localWidgetInfo = iter->second;
            // Stop sending the customization template
            localWidgetInfo.inCustomization = false;
            UpdateWidget(localWidgetInfo);
        }
    }
}

Now, when you deploy your widget, you should see the Customize widget button in the ellipses menu. Clicking on the customize button will display your customization template.

A screenshot showing the widgets customization UI.

Click the Reset counter button to reset the counter to 0. Click the Exit customization button to return to your widget's regular behavior.