Mouse scroll button on a quick report report

Updated 05/07/2016

I found this other tip in the Embarcadero forum, even simpler than the tip below.

procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG;
var Handled: Boolean);
var
    i: SmallInt;
    pt : Tpoint;
begin
    GetCursorPos(pt); // Get the position from Cursor
    if Msg.message = WM_MOUSEWHEEL then // WheelMouse Message when scrolling
    begin 
        Msg.lParam := 0;
        i := HiWord(Msg.wParam) ;
        if i > 0 then // If Scrolling Up
            SendMessage(WindowFromPoint(pt),WM_VSCROLL, SB_LINEUP,0) 
        else 
            SendMessage(WindowFromPoint(pt),WM_VSCROLL, SB_LINEDOWN,0);

        Handled := False;
    end;
end;

Second oldest tip

First, add a BeforePrint event to your report:

procedure Form1.QuickRep1BeforePrint(Sender: TCustomQuickRep;
  var PrintReport: Boolean);
begin
  SetupMouseWheel;
end;

Then, create the function SetupMouseWheel :

procedure Form1.SetupMouseWheel;
begin
  with TQRStandardPreview(Application.FindComponent('QRStandardPreview')) do
    begin
      OnMouseWheel := MouseWheel;
    end;
end;

Finally, create the function MouseWheel :

procedure Form1.MouseWheel(Sender: TObject; Shift: TShiftState;
  WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
begin
  with TQRStandardPreview(Application.FindComponent('QRStandardPreview')) do
  begin
    Application.ProcessMessages;
    VertScrollBar.Range := 1350;
    VertScrollBar.Position := VertScrollBar.Position - trunc(WheelDelta / 4);
  end;
end;

Replace QRStandardPreview in both functions with the name of your TQRPreview component.

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