/// <summary>
        /// Opens dialog to choose a projection.
        /// </summary>
        private void OnEditClick(object sender, EventArgs e)
        {
            int epsg = _context.ChooseEpsgProjection();

            if (epsg == -1)
            {
                return;
            }

            var sr = new SpatialReference();

            if (!sr.ImportFromEpsg(epsg))
            {
                MessageService.Current.Warn("Failed to initialize selected projection.");
                return;
            }

            textBoxExt1.Text = sr.ExportToWkt();
        }