modify.~pas

图书管理系统DELPHI版本

unit modify;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, DBCtrls, Mask, ExtCtrls, Buttons, DB, DBTables;

type
  Tmodifyfrm = class(TForm)
    GroupBox1: TGroupBox;
    BitBtn1: TBitBtn;
    Label1: TLabel;
    Bevel1: TBevel;
    Label2: TLabel;
    DBEdit2: TDBEdit;
    Label3: TLabel;
    DBEdit3: TDBEdit;
    Label4: TLabel;
    DBEdit4: TDBEdit;
    Label5: TLabel;
    DBEdit5: TDBEdit;
    Label6: TLabel;
    DBEdit6: TDBEdit;
    Label7: TLabel;
    DBEdit1: TDBEdit;
    Label8: TLabel;
    DBEdit7: TDBEdit;
    Label9: TLabel;
    DBEdit8: TDBEdit;
    Label10: TLabel;
    DBMemo1: TDBMemo;
    DataSource1: TDataSource;
    ComboBox1: TComboBox;
    Table1: TTable;
    procedure BitBtn1Click(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure ComboBox1Change(Sender: TObject);
    procedure Table1BeforePost(DataSet: TDataSet);
  private
    { Private declarations }
  procedure cancelmodified(var e:TDBEdit);
  public
    { Public declarations }
  end;

var
  modifyfrm: Tmodifyfrm;

implementation
   uses global;
{$R *.dfm}
procedure tmodifyfrm.cancelmodified(var e:TDBEdit);
begin
if e.Modified then e.Undo ;
end;


procedure Tmodifyfrm.BitBtn1Click(Sender: TObject);
begin
close;
end;

procedure Tmodifyfrm.FormShow(Sender: TObject);
begin
 table1.DatabaseName :=dbname ;
 table1.TableName :='book_info.db';
 table1.Open;
 combobox1.Items.Clear ;
 while not table1.Eof do
   begin
   combobox1.Items.Add(table1.fieldbyname('图书编号').AsString);
   table1.Next ;
   end;
 table1.First ;
 combobox1.ItemIndex :=0;
end;

procedure Tmodifyfrm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
table1.Close ;
end;

procedure Tmodifyfrm.ComboBox1Change(Sender: TObject);
begin
with table1 do
  begin
  setkey;
  fieldbyname('图书编号').AsString :=combobox1.Items[combobox1.itemindex];
  gotokey;
  end;
end;

procedure Tmodifyfrm.Table1BeforePost(DataSet: TDataSet);
begin
if messagedlg('数据已经修改，保存吗？',mtconfirmation,[mbYes,mbNo],0)=mrNo then
abort;
end;

end.