landunit.~pas

一个简单的数据库管理系统,是用delphi开发的.

unit LandUnit;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, ComCtrls, StdCtrls,
  Buttons, ExtCtrls,MainUnit;

type
  TLandForm = class(TForm)
    Panel1: TPanel;
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    ComboBox1: TComboBox;
    Bevel1: TBevel;
    CancelButton: TSpeedButton;
    YesButton: TSpeedButton;
    procedure CancelButtonClick(Sender: TObject);
    procedure YesButtonClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormShow(Sender: TObject);
    procedure Edit1KeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
  private
    CloseFlag: Boolean;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  LandForm: TLandForm;

implementation
uses PublicUnit, DataUnit;

{$R *.dfm}

procedure TLandForm.CancelButtonClick(Sender: TObject);
begin
  LoginFlag := True;
  Application.Terminate;
end;

procedure TLandForm.YesButtonClick(Sender: TObject);
begin
  if Trim(ComboBox1.Text) = '' then
  begin
    ShowMessage('请选择登录用户。');
    Exit;
  end;

  OpenSQL(DataForm.qryEdit,'Select * from UserInfo Where UserName = '+''''+Trim(ComboBox1.Text)+''' ');
  if Trim(Edit1.text) = Trim(DataForm.qryEdit.FieldByName('Pwd').AsString) then
  begin
    MainForm.StatusBar1.Panels[1].Text := Trim(ComboBox1.Text);
    CloseFlag := true;
    close;
  end else
  begin
    ShowMessage('用户口令输入错误，请重新输入。');
    Edit1.SelectAll;
    Edit1.SetFocus;
  end;
end;

procedure TLandForm.FormCreate(Sender: TObject);
begin
  CloseFlag := False;
end;

procedure TLandForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  DataForm.qryEdit.close;
  if Not CloseFlag then
    Application.Terminate;
end;

procedure TLandForm.FormShow(Sender: TObject);
var
  I:Integer;
  UserName:string;
begin                                     
  try
    LoginFlag := True;
    OpenSQL(DataForm.qryEdit,'Select Distinct * from userinfo');
    ComboBox1.Items.clear;
    DataForm.qryEdit.FindFirst;
    For I := 0 To DataForm.qryEdit.RecordCount -1 do
    begin
      UserName := Trim(DataForm.qryEdit.fieldbyname('UserName').AsString);
      ComboBox1.Items.Add(UserName);
      DataForm.qryEdit.FindNext;
    end;
  except
    ShowMessage('提取登录用户信息出错。');
    Exit;
  end;
end;

procedure TLandForm.Edit1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if key = 13 then YesButton.Click;
end;

end.