Mouse Scroll Within DBGrid

Author: admin | Category: Database, Tips and Tricks

//This is how we can make our DBGrid change the focus to previous or next record by scrolling mouse
//In this example we use an ADOTable, a Datasource and a DBGrid
 
unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Grids, DBGrids, ExtCtrls, DB, ADODB;
 
type
  TForm1 = class(TForm)
    DataSource1: TDataSource;
    ADOTable1: TADOTable;
    DBGrid1: TDBGrid;
    procedure FormCreate(Sender: TObject);
 
  private
    { Private declarations }
    OldGridProc: TWndMethod;
    procedure GridWindowProc(var Message: TMessage);
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.FormCreate(Sender: TObject);
begin
   ADOTable1.Active:=True;
   OldGridProc        := DBGrid1.WindowProc;
   DBGrid1.WindowProc := GridWindowProc;
end;
 
procedure TForm1.GridWindowProc(var Message: TMessage);
var
  Pos: SmallInt;
begin
  OldGridProc(Message);
  if Message.Msg = WM_VSCROLL then  //or WM_HSCROLL
  begin
    Pos          := Message.WParamHi;  //Scrollbox position
    ADOTable1.RecNo := Pos;
  end;
end;
 
end.
 

Tags: Database, DBGrid, Mouse