DELPHI的DBGrid 支持鼠标滚动

时间:2011-5-31来源:yang 作者: peng点击: 32次

unit Unit1;

interface

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

type
   TForm1 = class(TForm)
    DBGrid1: TDBGrid;
    ADOTable1: TADOTable;
    DataSource1: TDataSource;
    procedure FormCreate(Sender: TObject);
  private
   Procedure OnMouseWheel(Var Msg :TMsg;var Handled:Boolean);
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
//------------------------------------------------------------------------------
Procedure TForm1.OnMouseWheel(Var Msg :TMsg;var Handled:Boolean);
begin
  if Msg.message = WM_MouseWheel then
  begin
    if Msg.wParam > 0 then
     begin
       if DBGrid1.Focused then
         SendMessage(DBGrid1.Handle,WM_VSCROLL,SB_PAGEUP,0);
     end
    else
     begin
       if DBGrid1.Focused then
         SendMessage(DBGrid1.Handle,WM_VSCROLL,SB_PAGEDOWN,0);
     end;
    Handled:= True;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
 Application.OnMessage:=OnMouseWheel; // 截获鼠标滚动事件
end;

unit DBGrid3D;

interface

uses
  Windows, Messages, SysUtils, Classes, Controls, Grids, DBGrids;

type
  TDBGrid3D = class(TDBGrid)
  private
    { Private declarations }
  protected
    { Protected declarations }
  public
    { Public declarations }
  published
    function DoMouseWheel(Shift: TShiftState; WheelDelta: Integer; MousePos: TPoint): Boolean; override;
    { Published declarations }
  end;

procedure Register;

implementation


function TDBGrid3D.DoMouseWheel(Shift: TShiftState;
  WheelDelta: Integer; MousePos: TPoint): Boolean;
begin
  if WheelDelta < 0 then
    Datasource.DataSet.Next;
  if wheelDelta > 0 then
    DataSource.DataSet.Prior;
end;

procedure Register;
begin
  RegisterComponents(‘Samples‘, [TDBGrid3D]);
end;

end.

你只要将一个TApplication 控件放到窗体上
procedure Application1.OnMessage
(var Msg: TMsg; var Handled: Boolean) ;
var
i: SmallInt;
begin
  if Msg.message = WM_MOUSEWHEEL then
  begin
    Msg.message := WM_KEYDOWN;
    Msg.lParam := 0;
    i := HiWord(Msg.wParam) ;
    if i > 0 then
    Msg.wParam := VK_UP
    else
    Msg.wParam := VK_DOWN;
    
    Handled := False;
  end;
end;