This works fine

<TextBlock Name="textBlock1" TextWrapping="Wrap">
    <Bold>TextBlock</Bold> is designed to be <Italic>lightweight</Italic>,
    and is geared specifically at integrating <Italic>small</Italic> portions
    of flow content into a UI.
</TextBlock>

But I need the inner text to be a data binding to a string

Is this even possible ? I tried different things but I cannot make it work

<TextBlock Text="{Binding FormattedText}" TextWrapping="Wrap">
</TextBlock>

this does not work either

<TextBlock TextWrapping="Wrap">
    <Run Text="{Binding FormattedText}"/>
</TextBlock>

the Code behind is this:

public string FormattedText
{
    get { return _formattedText; }
    set
    {
        _formattedText = value;
        OnPropertyChanged(nameof(FormattedText));
    }
}
private string _formattedText;

public MyWpfClass()
{                
   this.InitializeComponent();
   FormattedText = "<Bold>TextBlock</Bold> is designed to be <Italic>lightweight</Italic>, and is geared specifically at integrating<Italic>small</Italic> portions of flow content into a UI.";
}

How can I get formatted text with code behind data binding ?

(The text needs to be a string, not a programmable initialization of a TextBlock)

Thanks for your help

thanks for your help