关于ListView指针Data介绍

关于TListView中的Data属性

赋值：
type
    PAllHidenDate = ^AllHidenDate;
    AllHidenDate = record
        PriceID: Integer;
        OrderNumber: string;
        State: Integer;
        PriceData: WideString;
    end;

var
    HidenData: PAllHidenDate;

begin
    with lvDataViewAll.Items.Add do
    begin
        HidenData := New(PAllHidenDate);
        HidenData.PriceID := StrToIntDef(Node.Attributes['PriceID'], 0);
        HidenData.State := StrToIntDef(Node.Attributes['State'], 1);
        HidenData.OrderNumber := Node.Attributes['PriceNumber'];
        HidenData.PriceData := Node.XML;
        Data := HidenData;
    end;
end;

释放Data:
procedure TOrderQuotation.lvDataViewAllDeletion(Sender: TObject; Item:
    TListItem);
var
    HidenData : PAllHidenDate;
begin
    if Item.Data = nil then Exit;
    HidenData := Item.Data ;
    Dispose(HidenData);
end;

释放内存时需要和赋值时的指针类型相同，不然会出错内存泄漏

 

 

PViewItemState = ^TViewItemState;
TViewItemState = Record
  ViewItemid: Integer;
end;

 

var
  nLoop: integer;
  li: TListItem;
  pp: PViewItemState;
begin
  for nLoop:=0 to 10 do
  begin
    li:=ListView1.items.add;
    li.caption:=IntToStr(nLoop);
    new(pp);
    li.Data:=pp;
  end;
end;

需释放内存

var
I : integer;
begin
  for I := 0 to TreeView.Items.Count - 1 do
  begin
    Dispose(TreeView.Items[I].Data);
    TreeView.Items[I].Data := nil;
  end;
end;