comparing two List<>

Question

i have gridview control with a checkbox on it

When i hit on save button i able to find the checkbox which have been checked and i able to do it so far so good but the pr

Answer 1

It sounds like what you need is set operations. You have a few choices:

.NET 4.0 - HashSet

http://msdn.microsoft.com/en-us/library/bb359438.aspx

.NET 3.5 - Linq extensions

The Linq to Objects extensions contains some set operations like Intersect and Union. http://msdn.microsoft.com/en-us/library/system.linq.enumerable.aspx

.NET 2.0 - SetList

In 2.0 you'll need to hand-roll something like the following SetList class. http://csharptest.net/browse/src/Library/Collections/SetList.cs (online-help)

To use SetList:

SetList listFromDB = new SetList(EmployeeListFromDB);
SetList selectedEmployee = new SetList(MySelectedEmployee);

SetList removed = listFromDB.SubtractSet(selectedEmployee);
SetList added = selectedEmployee.SubtractSet(listFromDB);

Note: Employee must implement IComparable, or you should write an IComparer and provide it to the SetList constructor calls above.