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What exactly is the difference between <listview.Clear> and <listview>.items.clear in delphi 7?

ListView.Clear is just a wrapper around ListView.Items.Clear with ListItems.BeginUpdate / ListItems.EndUpdate . look at the source:

procedure TCustomListView.Clear;
begin
  FListItems.BeginUpdate;
    FListItems.Clear;
  finally
    FListItems.EndUpdate;
From the docs:
  
The BeginUpdate method suspends screen repainting until the EndUpdate
  method is called. Use BeginUpdate to speed processing and avoid
  flicker while items are added to or deleted from a collection.
A better practice is to use BeginUpdate/EndUpdate for speed and avoiding flicker.

But the main reason to use ListView.Clear is because using a "high-level VCL methods" (As well commented by @Arnaud) is always a good idea, and the implementation might change  (BTW, the method was introduced in D7).
EDIT: I have tested the TListView with 10k Items (D7/WinXP):
ListView.Items.Clear: ~5500 ms
ListView.Clear: ~330 ms
Conclusion: ListView.Clear is about 16 times faster than ListView.Items.Clear when BeginUpdate/EndUpdate is not used!
                Actually, I don't think that BeginUpdate .. EndUpdate is of any help in the case of clear.
– jpfollenius
                Apr 16, 2012 at 7:20
                @Smasher Since clear release each object, it will notify each deletion to the VCL, unless the BeginUpdate / EndUpdate is used. This is the difference between the two, and why Clear is much faster than Items.Clear. It is always a good idea to call directly the high-level VCL methods, instead of going into the internal plumbing, unless you know exactly what you are doing.
– Arnaud Bouchez
                Apr 16, 2012 at 9:34
                @ArnaudBouchez, +1 for "high-level VCL methods". that was exactly the expression I was looking for.
– kobik
                Apr 16, 2012 at 9:42
ListView.Clear is a convenience method that calls ListView.Items.Clear internally. There is no semantic difference no matter which of the two you call.
I prefer the first one because it is shorter and it doesn't show the internal representation which is of no interest for me at this point.
                I expect no performance issue. The one just calls the other with the BeginUpdate .. EndUpdate not making a difference in this case (imho).
– jpfollenius
                Apr 16, 2012 at 7:21
                -1 for saying it is a mere convenience method without any other difference. There is clearly a difference.
– Rudy Velthuis
                Apr 16, 2012 at 12:10
        
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