Exception when linking to Microsoft Store Purchase API library from Blazor MAUI Windows App

Richard Freytag 56

Hi, I am have written multile Microsoft Store Apps in the UWP and WPF frameworks and published them to the Store. These apps all have to and do call the Microsoft Store Purchase API.

Now I'm building a Blazor MAUI Store App and have found apps in the framework can be published to and downloaded from the Microsoft App Store.

However, I encounter a conflict when attempting to call the Microsoft Store Purchase API from my new Blazor MAUI app. This is a critical problem for me.

When I try to write two simple lines in my Blazor MAUI, Home.razor file as follows ... Trying to write two simple lines in Home.razor

#if WINDOWS
            StoreContext sc = StoreContext.GetDefault();
            var result = await sc.RequestPurchaseAsync("9N35H09Z21");
#endif

It throws error :

 System.Runtime.InteropServices.COMException
  HResult=0x80070578
  Message=Invalid window handle. (0x80070578)
  Consider WindowNative, InitializeWithWindow
  Source=WinRT.Runtime

I also tried this call using the way I had earlier had success with in WPF ...

IInitializeWithWindow initWindow = (IInitializeWithWindow)(object)sc; initWindow.Initialize(System.Diagnostics.Process.GetCurrentProcess().MainWindowHandle);
An error occurred: System.InvalidCastException: Invalid cast from 'Windows.Services.Store.StoreContext' to 'MySecureNotes.Components.Pages.Home+IInitializeWithWindow'

Two questions:

Do I need to add any special nuget packages ?
Can anyone guide with a working example of how to call the Microsoft Store Purchase API from a Blazor MAUI apps that compiles?

Note: Although I'm developing a MAUI Blazor app, I'm currently limited to using it only on Windows. I am doing my development in VS Pro v17.11.2 with all libraries updated to their latest versions.

Thank you, very much,
Richard Freytag

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 30,746 Reputation points Microsoft Vendor

2024-09-09T09:42:14.9066667+00:00
I am have written multile Microsoft Store Apps in the UWP and WPF frameworks and published them to the Store.

MAUI uses using Windows UI Library (WinUI) 3.Do you set StoreContext like the following?

@code { private int currentCount = 0; private void IncrementCount() { currentCount++; #if WINDOWS StoreContext sc = StoreContext.GetDefault(); var result = await sc.RequestPurchaseAsync("9N35H09Z21"); #endif } }
Richard Freytag 56 Reputation points

2024-09-09T15:51:57.11+00:00

Yes, Wenyan Zhang, we do this in a similar way in our Blazor MAUI app. It does not run and gives the run-time error I listed above. What are you seeing?
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 30,746 Reputation points Microsoft Vendor

2024-09-10T07:18:52.0133333+00:00

There are no errors on my side, could you share more code snippets with me? In which method do you put the code snippets?
Jignesh Desai 101 Reputation points

2024-09-10T11:45:18.6+00:00

Hi Wenyan,

I've attached a screenshot for your convenience. Any clue or advice

Some debug window output, this might be of help.

'MauiApp1TestingStoreAPI.exe' (CoreCLR: clrhost): Loaded 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\8.0.8\System.Collections.NonGeneric.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.

Exception thrown: 'System.Runtime.InteropServices.COMException' in WinRT.Runtime.dll

WinRT information: This function must be called from a UI thread

An exception of type 'System.Runtime.InteropServices.COMException' occurred in WinRT.Runtime.dll but was not handled in user code

WinRT information: This function must be called from a UI thread

Invalid window handle. (0x80070578)

Consider WindowNative, InitializeWithWindow

See https://aka.ms/cswinrt/interop#windows-sdk

Regards

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Exception when linking to Microsoft Store Purchase API library from Blazor MAUI Windows App

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