Interactive Task Lists

Task-list markers render as checkboxes. They are display-only by default so selection and scrolling remain predictable. To make them interactive, set both IsTaskListInteractive and TaskListToggleCommand.

<markdown:MarkdownTextBlock Markdown="{Binding DocumentMarkdown}"
                            IsTaskListInteractive="True"
                            TaskListToggleCommand="{Binding ToggleTaskCommand}"
                            TextWrapping="Wrap" />

The command parameter is a MarkdownTaskListToggleRequest:

public ICommand ToggleTaskCommand { get; }

public DocumentViewModel()
{
    ToggleTaskCommand = new RelayCommand<MarkdownTaskListToggleRequest>(request =>
    {
        if (request is not null)
        {
            DocumentMarkdown = request.UpdatedMarkdown;
        }
    });
}

The example uses RelayCommand<T> from CommunityToolkit.Mvvm; any ICommand implementation works.

Request data

Property	Meaning
`SourceMarkdown`	Document before the toggle.
`UpdatedMarkdown`	Complete document with the task marker changed.
`MarkerOffset`	Zero-based source offset of the task marker.
`IsChecked`	New checkbox state.
`TaskText`	Text associated with the task item.

The control invokes the command only when it can construct a source-safe update and CanExecute accepts the request. If execution is rejected, the checkbox returns to its previous visual state.

Treat UpdatedMarkdown as the authoritative source replacement. Assign it to the same state that supplies the control's Markdown binding; the resulting rerender keeps source, task controls, and external editors synchronized.