MPTagThat.FileNameToTag.FileNameToTag.tabControl1_SelectedTabPageChanged C# (CSharp) Method

        private void tabControl1_SelectedTabPageChanged(object sender, Elegant.Ui.TabPageChangedEventArgs e)
        {
            if (sender == null)
              {
            return;
              }

              if ((sender as Elegant.Ui.TabControl).SelectedTabPage == tabPagePreview)
              {
            if (!_isPreviewFilled)
            {
              _isPreviewFilled = true;
              if (_previewForm == null)
              {
            _previewForm = new Preview();
            _previewForm.Dock = DockStyle.Fill;
            FillPreview();
            tabPagePreview.Controls.Add(_previewForm);
              }
              cbFormat_TextChanged(null, new EventArgs());
            }
              }
        }