Question

I am wondering why when I try to not add my object in the list when it’s duplicate it’s still adding it

if (thePreviousList.Contains(thePreviousItem))
{
}
else
{
    thePreviousList.Add(thePreviousItem);
}

For example thepreviousitem id = 1 and name = test
And if i have another object with the same id and same name it will still add it…

Answer 1

If you don’t want to override Equals, you can use LINQ to check if an object with the same ID and name (which is not necessarily the same object) already exists:

if (thePreviousList.Any(item => item.ID == thePreviousItem.ID
                             && item.Name == thePreviousItem.Name)) 
{ 
} 
else 
{ 
    thePreviousList.Add(thePreviousItem); 
}