C++/WinRT I'm using PropertyChanged to update textblock, but when clicked, crashed: Application called an interface that was marshalled for a different thread

[Extremeer]

Now I'm trying to use PropertyChangedEvent to test update the textblock, but when I click, it crashed: WinRT originate error - 0x8001010E : The application called an interface that was marshalled for a different thread.

//in WordArray.cpp

namespace winrt::Lexical_Frequency::implementation
{
    WordArray::WordArray(winrt::hstring const& allword) : m_allword{ allword }
    {
    }

    winrt::hstring WordArray::AllWord()
    { 
        return m_allword;
    }

    void WordArray::AllWord(winrt::hstring const& value)
    {
        if (m_allword != value)
        {
            m_allword = value;
            m_propertyChanged(*this, Windows::UI::Xaml::Data::PropertyChangedEventArgs{ L"AllWord" });
        }
    }
    
    winrt::event_token WordArray::PropertyChanged(Windows::UI::Xaml::Data::PropertyChangedEventHandler const& handler)
    {
        return m_propertyChanged.add(handler);
    }

    void WordArray::PropertyChanged(winrt::event_token const& token)
    {
        m_propertyChanged.remove(token);
    }
}

//in DataPage.xaml.cpp
namespace winrt::Lexical_Frequency::implementation
{
    DataPage::DataPage()
    {
        m_mainviewModel = winrt::make<Lexical_Frequency::implementation::WordArrayViewModel>();
        InitializeComponent();
    }

    void DataPage::ClickHandler(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e)
    {
        MainViewModel().WordArray().AllWord(L"xxx");
    }

    void DataPage::SaveFileButton_Click(IInspectable const&, RoutedEventArgs const&)
    {
        GetFileNameSave();
    }

    Lexical_Frequency::WordArrayViewModel DataPage::MainViewModel()
    {
        return m_mainviewModel;
    }
}

Now I'm trying to use MainViewModel().WordArray().AllWord(L"To Kill a Mockingbird"); to test update the textblock, but when I click, it crashed: WinRT originate error - 0x8001010E : The application called an interface that was marshalled for a different thread.