private void PopulateQuestionTree(bool isDelete)
{
tvQuestionList.BindingContext = null;
tvQuestionList.Nodes.Clear();
CustomDataCollectionQuestionDtoList questionList = new CustomDataCollectionQuestionDtoList();
questionList.DtoList = _customDataCollectionQuestionList.DtoList.Where(q =>
q.TrackingState != BaseDto.TrackingInfo.Deleted).OrderBy(q => q.Sequence).ToList();
for (int i = 0; i < questionList.DtoList.Count; i++)
{
if(tvQuestionList.Nodes.Contains(x=>x.Name!=questionList.DtoList[i].Name)
tvQuestionList.Nodes.Insert(i, CreateTreeNode(questionList.DtoList[i], i));
}
tvQuestionList.Refresh();
}