ut_data.pas

罗小平<<delphi精要>>一书源码

unit UT_DATA;

interface

uses
  Windows, Classes, Controls, Forms,
  Buttons, ExtCtrls, StdCtrls, Grids, DBGrids,
  DB, DBTables;

type
  TFM_DATA = class(TForm)
    pEdit: TPanel;
    pDataParent: TPanel;
    pDCParent: TPanel;
    pDC: TPanel;
    pMod: TPanel;
    bAdd: TBitBtn;
    bModify: TBitBtn;
    bDelete: TBitBtn;
    pCommit: TPanel;
    bCommit: TBitBtn;
    bCancle: TBitBtn;
    pData: TPanel;
    DBGrid1: TDBGrid;
    procedure bAddClick(Sender: TObject);
    procedure bModifyClick(Sender: TObject);
    procedure bDeleteClick(Sender: TObject);
    procedure bCommitClick(Sender: TObject);
    procedure bCancleClick(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    thisDataSet: TDataSet;
    procedure SetMode(Mode: Word);
  published
  end;

var
  FM_DATA: TFM_DATA;

implementation


{$R *.dfm}


//------------------------------------------------------------------------------
//自定义过程部分
//------------------------------------------------------------------------------
procedure TFM_DATA.SetMode(Mode: Word);
begin
  case Mode of
    0://浏览
      pMod.BringToFront;
    1://编辑
      pCommit.BringToFront;
  end;
end;

//------------------------------------------------------------------------------
//事件部分
//------------------------------------------------------------------------------
procedure TFM_DATA.bAddClick(Sender: TObject);
begin
  thisDataSet.Append;
  SetMode(1);
end;
//------------------------------------------------------------------------------
procedure TFM_DATA.bModifyClick(Sender: TObject);
begin
  thisDataSet.Edit;
  SetMode(1);
end;
//------------------------------------------------------------------------------
procedure TFM_DATA.bDeleteClick(Sender: TObject);
begin
  thisDataSet.Delete;
end;
//------------------------------------------------------------------------------
procedure TFM_DATA.bCommitClick(Sender: TObject);
var
  DataSetType: Word;
begin
  if thisDataSet is TTable then DataSetType := 1
  else if thisDataSet is TQuery then DataSetType := 2
  else DataSetType := 0;

  if DataSetType <> 0 then
  with TDBDataSet(thisDataSet).Database do
  try
    if not InTransaction then StartTransaction;
    thisDataSet.Post;
    Commit;
    with thisDataSet do
    case DataSetType of
      1: Refresh;
      2:
      begin
        Close;
        Open;
      end;
    end;
  except
    Rollback;
  end;
end;
//------------------------------------------------------------------------------
procedure TFM_DATA.bCancleClick(Sender: TObject);
begin
  thisDataSet.Cancel;
  SetMode(0);
end;
//------------------------------------------------------------------------------
procedure TFM_DATA.FormCreate(Sender: TObject);
begin
  try
    thisDataSet := DBGrid1.DataSource.DataSet;
  except
    MessageBox(0,'数据源设置不正确。','提示',
      MB_ICONINFORMATION+MB_OK);
  end;
end;
//------------------------------------------------------------------------------
procedure TFM_DATA.FormCloseQuery(Sender: TObject;
  var CanClose: Boolean);
begin
  if thisDataSet.State in [dsEdit,dsInsert] then
  begin
    case MessageBox(0,'保存变动过的数据吗？','请选择',
          MB_ICONQUESTION+MB_YESNOCANCEL) of
      IDYES:  bCommit.Click;
      IDNO:  bCancle.Click;
      IDCANCEL: CanClose := False;
    end;
  end;
end;
//------------------------------------------------------------------------------
end.