C++/WinRT How to clean and bind strings again to a Textbox after it changed?

[Extremeer]

in C++/WinRT.
I have 2 strings in a global struct and they will be changed by a global function. I want to bind those 2 strings in struct to a listview automaticaly after it changed, but now can just bind some static and default data.
I don't know how to clean previous text in the textboxs and bind the new string to the new textbox after the strings changed.

some code:

struct word_group
{
	char* word_text;
	int word_num;
	int word_place;
};
struct word_group GROUP[SIZE];

//in WordArrayViewModel.h

#pragma once
#include "WordArrayViewModel.g.h"
#include "WordArray.h"

namespace winrt::Lexical_Frequency::implementation
{
    struct WordArrayViewModel : WordArrayViewModelT<WordArrayViewModel>
    {
        winrt::Lexical_Frequency::WordArray DefaultWordArray();
        WordArrayViewModel();
        Windows::Foundation::Collections::IVector<Windows::Foundation::IInspectable> WordArrays();

    private:
        Windows::Foundation::Collections::IVector<Windows::Foundation::IInspectable> m_wordarrays;
    private:
        Lexical_Frequency::WordArray m_defaultWordArray{ nullptr };
    };
}
namespace winrt::Lexical_Frequency::factory_implementation
{
    struct WordArrayViewModel : WordArrayViewModelT<WordArrayViewModel, implementation::WordArrayViewModel>
    {
    };
}

//in WordArrayViewModel.cpp

#include "pch.h"
#include "WordArrayViewModel.h"
#if __has_include("WordArrayViewModel.g.cpp")
#include "WordArrayViewModel.g.cpp"
#endif

namespace winrt::Lexical_Frequency::implementation
{
    Lexical_Frequency::WordArray WordArrayViewModel::DefaultWordArray()
    {
        m_defaultWordArray = winrt::make<WordArray>(L"iPhone", L"128");
        return m_defaultWordArray;
    }
    WordArrayViewModel::WordArrayViewModel()
    {
        std::vector<Windows::Foundation::IInspectable> wordarrays;

        wordarrays.push_back(winrt::make<WordArray>(L"Abandon", L"120"));

        wordarrays.push_back(winrt::make<WordArray>(L"Bird", L"90"));

        wordarrays.push_back(winrt::make<WordArray>(L"Cat", L"8"));

        m_wordarrays = winrt::single_threaded_observable_vector<Windows::Foundation::IInspectable>(std::move(wordarrays));
    }

    Windows::Foundation::Collections::IVector<Windows::Foundation::IInspectable> WordArrayViewModel::WordArrays() { return m_wordarrays; }
}

//in WordArray.h

#pragma once
#include "WordArray.g.h"
#include <sstream>

namespace winrt::Lexical_Frequency::implementation
{
    struct WordArray : WordArrayT<WordArray>
    {
        WordArray(hstring const& allword, hstring const& allnumber);
        hstring AllWord();
        void AllWord(hstring const& value);
        hstring AllNumber();
        void AllNumber(hstring const& value);
    private:
        std::wstring m_allword;
        std::wstring m_allnumber;
    };
}
namespace winrt::Lexical_Frequency::factory_implementation
{
    struct WordArray : WordArrayT<WordArray, implementation::WordArray>
    {
    };
}

//in WordArray.cpp

#include "pch.h"
#include "WordArray.h"
#if __has_include("WordArray.g.cpp")
#include "WordArray.g.cpp"
#endif

namespace winrt::Lexical_Frequency::implementation
{
    void WordArray::AllWord(hstring const& value)
    {
        throw hresult_not_implemented();
    }
    void WordArray::AllNumber(hstring const& value)
    {
        throw hresult_not_implemented();
    }
    WordArray::WordArray(hstring const& allword, hstring const& allnumber) : 
        m_allword{ allword.c_str() },
        m_allnumber{ allnumber.c_str() }{}

    hstring WordArray::AllWord() { return hstring{ m_allword }; }
    hstring WordArray::AllNumber() { return hstring{ m_allnumber }; }
}

//in Page.xmal
<ListView.ItemTemplate>
                    <DataTemplate x:Name="TableDataTemplate" x:DataType="local:WordArray">
                            <TextBlock Grid.Column="1" VerticalAlignment="Center" HorizontalTextAlignment="Center" Text="{x:Bind AllWord}" />
                            <TextBlock Grid.Column="2" VerticalAlignment="Center" HorizontalTextAlignment="Center" Text="{x:Bind AllNumber}"/>
                    </DataTemplate>
</ListView.ItemTemplate>

I don't know how to clean previous text in the textboxs and bind the new string to the new textbox after the strings changed.