Question

objTempList = objParentList;
foreach (var item in objTempList)
{
    objChildList = objList.AsQueryable()
                          .Where(x => x._parentId == item.filedbid)
                          .ToList<FileObjectView>();
    if (objChildList != null)
    {
        foreach (var child in objChildList)
        {
            objParentList.Add(child);
        }
    }
}

Above is my code, problem is the assignment of objTempList = objParentList

objParentList has 10 rows which are assigned to objTempList
now in next step when i am doing foreach and adding more rows in objParentList its automaticaly reflecting in list objTempList and my loop is giving error message.

Answer 1

You should separate list instances to avoid this error

objTempList = objParentList.ToList();
foreach (var item in objTempList) 
{ 
   objChildList = objList.AsQueryable().Where(x => x._parentId == item.filedbid).ToList(); 
   foreach (var child in objChildList)
      objParentList.Add(child);       
}