updateform.pas

Delphi7从入门到精通及附书源码 Delphi7从入门到精通及附书源码

unit UpdateForm;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  IBDatabase, Db, IBCustomDataSet, IBUpdateSQL, IBQuery, DBTables,
  ExtCtrls, DBCtrls, Grids, DBGrids, DBActns, ActnList, ComCtrls, ToolWin;

type
  TForm1 = class(TForm)
    EmpDS: TDataSource;
    IBQuery1: TIBQuery;
    IBUpdateSQL1: TIBUpdateSQL;
    IBDatabase1: TIBDatabase;
    IBTransaction1: TIBTransaction;
    DBGrid1: TDBGrid;
    IBDataSet1: TIBDataSet;
    ActionList1: TActionList;
    DataSetCancel1: TDataSetCancel;
    DataSetDelete1: TDataSetDelete;
    DataSetEdit1: TDataSetEdit;
    DataSetFirst1: TDataSetFirst;
    DataSetInsert1: TDataSetInsert;
    DataSetLast1: TDataSetLast;
    DataSetNext1: TDataSetNext;
    DataSetPost1: TDataSetPost;
    DataSetPrior1: TDataSetPrior;
    DataSetRefresh1: TDataSetRefresh;
    acCommit: TAction;
    acRollback: TAction;
    ToolBar1: TToolBar;
    ToolButton1: TToolButton;
    ToolButton2: TToolButton;
    ToolButton3: TToolButton;
    ToolButton4: TToolButton;
    ToolButton5: TToolButton;
    ToolButton6: TToolButton;
    ToolButton7: TToolButton;
    ToolButton8: TToolButton;
    ToolButton10: TToolButton;
    ToolButton11: TToolButton;
    ToolButton12: TToolButton;
    ToolButton9: TToolButton;
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure ActionUpdateTransactions(Sender: TObject);
    procedure acCommitExecute(Sender: TObject);
    procedure acRollbackExecute(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

uses
  Registry;

procedure TForm1.FormCreate(Sender: TObject);
var
  Reg: TRegistry;
begin
  Reg := TRegistry.Create;
  try
    Reg.RootKey := HKEY_LOCAL_MACHINE;
    Reg.OpenKey('\Software\Borland\Borland Shared\Data', False);
    IBDatabase1.DatabaseName := Reg.ReadString('Rootdir') + '\employee.gdb';
  finally
    Reg.Free;
  end;
  EmpDS.DataSet.Open;
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
var
  nCode: Word;
begin
  if IBTransaction1.InTransaction then
  begin
    nCode := MessageDlg ('Commit Transaction? (No to rollback)',
      mtConfirmation, mbYesNoCancel, 0);
    case nCode of
      mrYes: IBTransaction1.Commit;
      mrNo: IBTransaction1.Rollback;
      mrCancel: Action := caNone; // don't close
    end;
  end;
end;

procedure TForm1.ActionUpdateTransactions(Sender: TObject);
begin
  acCommit.Enabled := IBTransaction1.InTransaction;
  acRollback.Enabled := acCommit.Enabled;
end;

procedure TForm1.acCommitExecute(Sender: TObject);
begin
  IBTransaction1.CommitRetaining;
end;

procedure TForm1.acRollbackExecute(Sender: TObject);
begin
  // or: IBTransaction1.RollbackRetaining;
  IBTransaction1.Rollback;
  IBTransaction1.StartTransaction;
  EmpDS.DataSet.Open;
end;

end.