public string Text { get; }

<DxRichEdit @ref="richEdit" />

@code {
    DxRichEdit richEdit;
    Document documentAPI;

    protected override Task OnAfterRenderAsync(bool firstRender) {
        if (firstRender)
            InitializeDocument();
        return base.OnAfterRenderAsync(firstRender);
    }

    async void InitializeDocument() {
        /* Surround the code that contains an asynchronous operation with a try-catch block to handle
        the OperationCanceledException. This exception is thrown when an asynchronous operation is cancelled. */
        try {
            documentAPI = richEdit.DocumentAPI;
            for (int i = 2; i < 6; i++) {
                await documentAPI.Paragraphs.CreateAsync();
                await documentAPI.AddTextAsync("New Paragraph " + i.ToString());
            }
            IReadOnlyList<Paragraph> paragraphs = await documentAPI.Paragraphs.GetAllAsync();
            Paragraph curParagraph;
            int position;
            for (int i = 0; i < paragraphs.Count; i++) {
                curParagraph = await documentAPI.Paragraphs.GetAsync(i);
                TextSpan currentCharacters = await documentAPI.GetTextSpanAsync(curParagraph.Interval);
                position = curParagraph.Interval.Start + currentCharacters.Text.IndexOf("New ");
                await documentAPI.RemoveAsync(position, 4);
            }
        }
        catch (OperationCanceledException e) {
            Console.WriteLine($"{nameof(OperationCanceledException)} thrown with message: {e.Message}");
        }
    }
}