Deleting selected item in TListView

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August 27th, 2004, 01:08 AM

Biopsy

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Deleting selected item in TListView

For some reason, when i try to delete a selected item in the TListView, i get EAccessViolation Error. But the code still deletes the selected item. Here is what i have.

Code:

procedure TForm1.Button6Click(Sender: TObject);
var
  i: integer;
begin
try
  with Listview1 do
    for i := 0 to Items.Count - 1 do
      if Items[i].Selected then
      Items.Delete(Items.IndexOf(FindCaption(0, Items[i].Caption, False, True, False)));
        except on EAccessViolation do
        // silent
        end;
        end;

I had to catch the exception to make it stop showing that error message. But why is it causing it? The code seems to be fine and logical. Any help would be appreciated. Thank you!

August 27th, 2004, 01:28 AM

rossM

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Try using Listview1.DeleteSelected; instead.

August 27th, 2004, 01:33 AM

Biopsy

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Quote:

Originally Posted by rossM

Try using Listview1.DeleteSelected; instead.

It doesn't have that property. Must be a new version of TListView. I'm using Delphi 5.
All it has is the Delete(); procedure.

August 27th, 2004, 01:40 AM

rossM

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Does it have a Selected property?

Code:

Listview1.Selected.Delete;

August 27th, 2004, 01:46 AM

Biopsy

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Quote:

Originally Posted by rossM

Does it have a Selected property?

Code:

Listview1.Selected.Delete;

haha... jesus, i am an idiot. I don't know how i didn't see that. lol... I still wonder why my method didn't work though.

but thanks a lot!!

August 27th, 2004, 02:08 AM

rossM

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It's because when you delete an item, Items.Count reduces by 1 but the number of iterations of the for loop does not decrease and you get the exception when trying to access an item past the end of the list. If you use a while loop like this then it works:

Code:

var
  i: Integer;
begin
  with Listview1 do
  begin
    i := 0;
    while i < Items.Count do
      if Items[i].Selected then
        Items.Delete(Items.IndexOf(
          FindCaption(0, Items[i].Caption, False, True, False)))
      else
        Inc(i);
  end;

Deleting selected item in TListView

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