Fórum Navegação de registros perfeita usando ADODataSet #301906

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, ADODB,
  StdCtrls;

type
  TForm1 = class(TForm)
    btnPrimeiro: TButton;
    btnAnterior: TButton;
    btnProximo: TButton;
    btnUltimo: TButton;
    Edit1: TEdit;
    procedure FormDestroy(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure btnPrimeiroClick(Sender: TObject);
    procedure btnAnteriorClick(Sender: TObject);
    procedure btnProximoClick(Sender: TObject);
    procedure btnUltimoClick(Sender: TObject);
  private
    { Private declarations }
    ADOConexao: _connection;
    ADORecordSet: _Recordset;
    procedure Mostra;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses
 ADOInt;

procedure TForm1.FormCreate(Sender: TObject);
begin
  ADOConexao := CoConnection.Create;
  ADORecordSet := CoRecordSet.Create;

  ADOConexao.CursorLocation := adUseClient;
  ADORecordSet.CursorLocation := adUseClient;
  ADORecordSet.CursorType := adOpenStatic;
  ADORecordSet.LockType := adLockOptimistic;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  ADORecordSet.Close;
  ADORecordSet := nil;
  ADOConexao.Close;
  ADOConexao := nil;
end;

procedure TForm1.FormShow(Sender: TObject);
begin
  ADOConexao.Open(´Provider=Microsoft.Jet.OLEDB.4.0;Data Source=bd1.mdb;Persist Security Info=False´, ´´, ´´, 0);
  ADORecordSet.Open(´select nome from tabela´, ADOConexao, adOpenStatic, adLockOptimistic, -1);
  if ADORecordSet.RecordCount > 0 then
    Mostra;
end;

procedure TForm1.Mostra;
begin
  Edit1.Text := VarToStr(ADORecordSet.Fields[´nome´].Value);
end;

procedure TForm1.btnPrimeiroClick(Sender: TObject);
begin
  if ADORecordSet.AbsolutePosition <= 1 then
    Exit;
    
  ADORecordSet.MoveFirst;
  Mostra;
end;

procedure TForm1.btnAnteriorClick(Sender: TObject);
begin
  if ADORecordSet.AbsolutePosition <= 1 then
    Exit;

  ADORecordSet.MovePrevious;
  Mostra;
end;

procedure TForm1.btnProximoClick(Sender: TObject);
begin                           
  if (ADORecordSet.AbsolutePosition = ADORecordSet.RecordCount) or (ADORecordSet.AbsolutePosition = -1) then
    Exit;
    
  ADORecordSet.MoveNext;
  Mostra;    
end;

procedure TForm1.btnUltimoClick(Sender: TObject);
begin
  if (ADORecordSet.AbsolutePosition = ADORecordSet.RecordCount) or (ADORecordSet.AbsolutePosition = -1) then
    Exit;

  ADORecordSet.MoveLast;
  Mostra;  
end;

end.