private void OpenFileDialog_FileOk(object sender, CancelEventArgs e)
 {
     bendings = ExportXml.ReadXml(openFileDialog1.FileName);
     DrawBendingGroup(bendings);
 }
 private void SaveFileDialog_FileOk(object sender, CancelEventArgs e)
 {
     ExportXml.GenerateXml(bendings, saveFileDialog1.FileName);
 }