CODEWITHSUNDEEP
delphivcldbgrid
Vlad
Vlad

Reputation: 347

DBGrid scroll page instead of row

Well I have an issue with DBGrid vertical scrolling. When I scroll it vertically with mousewheel or vertical scrollbar it moves selected row up and down. I want to make it scroll not selected row but entire grid. Just like it works in Microsoft Excel for example (just to let you know what I mean). Any suggestions?

Upvotes: 3

Views: 7572

Answers (2)

Vlad
Vlad

Reputation: 347

Well, almost what I'd like to see. Found the post of hanuleye on swissdelhicenter.ch. This code let's you freely scroll DBGrid with mouse wheel.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Grids, DBGrids, DB, DBTables;

type
  TForm1 = class(TForm)
    DataSource1: TDataSource;
    Table1: TTable;
    DBGrid1: TDBGrid;
    procedure FormCreate(Sender: TObject);
    procedure DBGridMouseWheel(Sender: TObject; Shift: TShiftState;
      WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

  TWheelDBGrid = class(TDBGrid)
  public
    property OnMouseWheel;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  TWheelDBGrid(DBGrid1).OnMouseWheel := DBGridMouseWheel;
end;

function GetNumScrollLines: Integer;
begin
  SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, @Result, 0);
end;

procedure TForm1.DBGridMouseWheel(Sender: TObject; Shift: TShiftState;
  WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
var
  Direction: Shortint;
begin
  Direction := 1;
  if WheelDelta = 0 then
    Exit
  else if WheelDelta > 0 then
    Direction := -1;

  with TDBGrid(Sender) do
  begin
    if Assigned(DataSource) and Assigned(DataSource.DataSet) then
      DataSource.DataSet.MoveBy(Direction * GetNumScrollLines);
    Invalidate;
  end;
end;

end.

Upvotes: 1

zz1433
zz1433

Reputation: 3586

I don't think that's possible, since to me it seems that scrollbar on DBGrids are more like a progress indicator rather than a scroll. It behaves differently from the scrolls in ListViews where you scroll "pages", in the db controls even if you move up or down a single row the scrollbar changes to reflect the "current row"/"total rows" fraction

Upvotes: 0

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