change.pas

学生管理系统的课程设计报告

unit change;

interface

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

type
  Tfrmchange = class(TForm)
    DBGrid1: TDBGrid;
    Bevel1: TBevel;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    BitBtn1: TBitBtn;
    GroupBox1: TGroupBox;
    Label4: TLabel;
    Label5: TLabel;
    Label6: TLabel;
    Label7: TLabel;
    dbnchange: TDBNavigator;
    dbrgchange: TDBRadioGroup;
    DBMdesc: TDBMemo;
    dschange: TDataSource;
    dsstudent: TDataSource;
    dsclass: TDataSource;
    tblchange: TTable;
    tblstudent: TTable;
    tblclass: TTable;
    dbeCID: TDBEdit;
    dbestudentID: TDBEdit;
    dberecdate: TDBEdit;
    DBTname: TDBText;
    DBTsex: TDBText;
    DBTbirthdat: TDBText;
    DBTclass: TDBText;
    Query1: TQuery;
    procedure dbnchangeClick(Sender: TObject; Button: TNavigateBtn);
    procedure tblchangeAfterScroll(DataSet: TDataSet);
    procedure FormCreate(Sender: TObject);
    procedure dbeCIDKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure BitBtn1Click(Sender: TObject);
    procedure tblchangeBeforeDelete(DataSet: TDataSet);


  private
  procedure ToggleMode;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmchange: Tfrmchange;

implementation

uses MAIN;

{$R *.dfm}

procedure Tfrmchange.ToggleMode;
   procedure enableInput(enabled:boolean);
     begin
     dbeCID.Enabled:=enabled;
     dbestudentID.Enabled:=enabled;
     dberecdate.Enabled:=enabled;
     dbrgchange.Enabled:=enabled;
     dbmDesc.Enabled:=enabled;
    end;
  begin
   case tblchange.State of
      dsinsert,dsedit:
      begin
       enableInput(true);
       dbnchange.VisibleButtons:=[nbpost,nbcancel];
       dbecid.SetFocus;
       dberecdate.Text:=datetostr(date);
      end;
   else
    begin
     enableInput(false);
     dbnchange.VisibleButtons:=[nbfirst,nbprior,nbnext,nblast,nbinsert,nbdelete,nbedit,nbpost,nbcancel,nbrefresh];
     end;
     end;

  end;

procedure Tfrmchange.dbnchangeClick(Sender: TObject; Button: TNavigateBtn);
begin
 ToggleMode;
end;

procedure Tfrmchange.tblchangeAfterScroll(DataSet: TDataSet);
begin
ToggleMode;
end;

procedure Tfrmchange.FormCreate(Sender: TObject);
begin
   tblchange.Active:=true;
   if not tblchange.Eof then
    begin
    tblstudent.Active:=true;
    tblclass.Active:=true;
    end;
end;
procedure Tfrmchange.dbeCIDKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
 if key=13  then
   begin
   Query1.Close;
   Query1.SQL.Clear;
   query1.SQL.Add('select * from change  where cid=:str');
   query1.ParamByName('str').AsString:=dbecid.Text;
   Query1.open;
   if  not Query1.Eof then
     begin
     showmessage('记录号已经存在,请从新输入！');
     dbeCID.SetFocus;
     end
     else
     begin
     dbestudentid.SetFocus;
     end;
   end;
  end;

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

procedure Tfrmchange.tblchangeBeforeDelete(DataSet: TDataSet);
 var str:string;
 begin
 str:='确定要删除此条记录吗?';
 if messageDlg(str,mtconfirmation,[mbyes,mbno],0)<>mryes then
 abort;
end;

end.