winrt-api | WinRT reference content for developing Microsoft Universal | Runtime Evironment library

I am following the BookStore data binding example, documented at XAML controls; bind to a C++/WinRT property, up to and including the "Bind the button to the Title property" section.

My starting point is a new "Blank App, Packaged (WinUI 3 in Desktop)" project in Visual Studio.

[EDIT] Starting from a "Blank App (C++/WinRT)" project, which is for UWP apps, works perfectly. The problem persists with "WinUI 3 in Desktop" projects.

The initial data binding works and the button content L"Atticus" is read from the BookSku title property. However calling MainViewModel().BookSku().Title(L"To Kill a Mockingbird"); in the click handler, as directed in article, throws the exception

Exception thrown at 0x00007FFC801B4ED9 (KernelBase.dll) in BookStore.exe: WinRT originate error - 0x8001010E : 'The application called an interface that was marshalled for a different thread.'.

Stepping through the code, the call

m_propertyChanged(*this, Windows::UI::Xaml::Data::PropertyChangedEventArgs{ L"Title" });

in void BookSku::Title(hstring const& value) is where the exception is thrown from within.

I can change the button content manually, not through the binding property.

The first example in the Data binding in depth article describes a very similar, though slightly less complicated, data binding scenario. It throws the same exception.

I am using latest Microsoft.Windows.CppWinRT version 2.0.210825.3 and Windows App SDK version 0.8.3

I would like to allow the user to connect to paired audio devices directly from the app instead of navigating to the bluetooth settings manually.

I am successfully listing all bluetooth devices using WinRT Apis:

I would like to use OpenSSL-1.1.1g in a C++/WinRT project. So i created a test project. The below is what did i do in this project:

1.Install C++/WinRT in VS2019

2.Create project "TestOpenSSL1.1.1g" in the directory "c:\temp" (File->New->Project->Blank App(C++/WinRT))

3.Install Strawberry Perl and NASM

4.Download OpenSSL-1.1.1g and extract it to "c:\temp\openssl-1.1.1g"

5.Open "Developer Command Prompt for VS 2019" with "Run as Administrator"

6.Enter the directory "openssl-1.1.1g"

cd c:\temp\openssl-1.1.1g

7.Configure openssl

perl configure VC-WIN32 --prefix="c:\temp\TestOpenSSL1.1.1g\openssl-1.1.1g"

8.Compile openssl

nmake

9.Install openssl

nmake install

10.So i saw the directories "bin" "html" "include" "lib" were created in "c:\temp\TestOpenSSL1.1.1g\openssl-1.1.1g"

11.Include openssl header files

Add "$(ProjectDir)..\openssl-1.1.1g\include" in Solution Explorer->Properties->Configuration properties->C/C++ ->General->Additional include directories

12.Add dependencies "libcrypto.lib" and "libssl.lib"

Add "$(ProjectDir)..\openssl-1.1.1g\lib\libcrypto.lib;$(ProjectDir)..\openssl-1.1.1g\lib\libssl.lib" in Solution Explorer->Properties->Configuration properties->Linker->Input->Additional dependencies

13.Modify MainPage.cpp

#include

Add statement "OPENSSL_init();" in function "MainPage::MainPage";

After all these I built this project, there was no error. but if i debug this project the errors came:

This error happens to me when I use the helper function from microsoft docs to migrate to winrt from cx. I see a similar question here, but the solution mentioned doesn't seem to work for me. The solution mentioned here add #include before any other winrt headers in the file which has this error.

File.h:

I am porting my project from C++/CX to C++/WinRT. For this I need to do some interop stuff like this: https://docs.microsoft.com/en-us/windows/uwp/cpp-and-winrt-apis/interop-winrt-cx.

Microsoft recommends using helper functions like these for interoperability.

from_cx and to_cx functions The helper function below converts a C++/CX object to an equivalent C++/WinRT object. The function casts a C++/CX object to its underlying IUnknown interface pointer. It then calls QueryInterface on that pointer to query for the default interface of the C++/WinRT object. QueryInterface is the Windows Runtime application binary interface (ABI) equivalent of the C++/CX safe_cast extension. And, the winrt::put_abi function retrieves the address of a C++/WinRT object's underlying IUnknown interface pointer so that it can be set to another value.