private void AddButton_Clicked(object sender, EventArgs e)
        {
            Author author = new Author {
                AuthorDate        = Date.Date,
                AuthorName        = AuthorName.Text,
                AuthorDescription = AuthorInfo.Text,
                AuthorPhoto       = AuthorPhoto.Text
            };

            int i = DataAccess.AuthorInsert(author);

            if (i > 0)
            {
                DisplayAlert("ADD", "Author was add", "OK");

                AuthorName.Text = "";
                AuthorInfo.Text = "";
            }
            else
            {
                DisplayAlert("ADD", "Author wasn't add", "OK");
            }
        }