Listview Helper

gistfile1.pas

unit ListviewHelper;

interface

uses System.SysUtils, Vcl.ComCtrls;

type
  TListviewHelper = class helper for TListview
  public
    procedure SetRowCount(Count: Integer; Compacted: Boolean = False);
    function UpdateRow(Idx: integer; LvData:  TArray<string>;
      UpdateCaption: boolean = True): boolean;
end;

implementation


procedure TListviewHelper.SetRowCount(Count: Integer; Compacted: Boolean = False);
var
  i: integer;
begin
  if Count < 0 then
    Count := 0;

  while (Items.Count < Count) do
    with Items.Add do
      for i := 1 to Columns.Count - 1 do
        SubItems.Add('');

  if Compacted then
    for i := Items.Count - 1 downto Count do
      Items.Delete(i);
end;


function TListviewHelper.UpdateRow(Idx: integer;
  LvData:  TArray<string>;
  UpdateCaption: boolean = True): boolean;
var
  i: Integer;
begin
  Result := False;

  with Items[Idx] do
  begin
    if (UpdateCaption) and (Caption <> LvData[0]) then
      Caption := LvData[0];

    for i := 1 to Columns.Count - 1 do
    begin
      if (i <= High(LvData)) then
      begin
        if (SubItems[i - 1] <> LvData[i]) then
          SubItems[i - 1] := LvData[i];
      end
      else
        SubItems[i - 1] := '';
    end;
  end;
end;


end.

usage:
listview1.SetRowCount(100);
for i := 1 to 100 do
listview1.UpdateRow(i-1 ,[ i.tostring , random(100).tostring ]);