delphi＋sql办公自动化系统（＋开题报告源程序＋(4)

procedure TfrmLogIn.ComboBox2DropDown(Sender: TObject);
begin
  if ComboBox1.ItemIndex<0 then
   begin
     ShowMessage('请先选择该用户所在的部门!');
     Exit;
   end;
 ComboBox2.Items.Clear;
   with dm.AQDept do
    begin
      close;
      sql.Clear;
      sql.Add('select * from Users where Department='''+Trim(comboBox1.Text)+'''');
      open;
      first;
      while not dm.AQDept.Eof do
       begin
         ComboBox2.Items.Add(dm.AQDept.FieldValues['UserName']);
         dm.AQDept.Next;
       end;
    end;
  
end;

end.

客户信息界面与代码设计实现
unit Ucustom;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, StdCtrls, ExtCtrls, Buttons, Grids, DBGrids, ImgList,
  Menus, Mask, DBCtrls;

type
  TfrmCustomer = class(TForm)
    Panel2: TPanel;
    Splitter1: TSplitter;
    GroupBox2: TGroupBox;
    GroupBox3: TGroupBox;
    bbtnNew: TBitBtn;
    bbtnModify: TBitBtn;
    bbtnDel: TBitBtn;
    bbtnExit: TBitBtn;
    ImageList1: TImageList;
    GroupBox4: TGroupBox; （转载自http://zw.ＮＳＥaＣ.com科教作文网）
    DBGrid3: TDBGrid;
    PopupMenu1: TPopupMenu;
    A1: TMenuItem;
    B1: TMenuItem;
    C1: TMenuItem;
    N5: TMenuItem;
    N6: TMenuItem;
    N8: TMenuItem;
    GroupBox5: TGroupBox;
    DBGrid1: TDBGrid;
    GroupBox1: TGroupBox;
    TreeView1: TTreeView;
    HeaderControl1: THeaderControl;
    ComboBox1: TComboBox;
    Edit8: TEdit;
    DBEdit4: TDBEdit;
    DBEdit9: TDBEdit;
    DBGrid2: TDBGrid;
    bbtnShowAll: TBitBtn;
    procedure bbtnNewClick(Sender: TObject);
    procedure bbtnModifyClick(Sender: TObject);
    procedure bbtnExitClick(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure ComboBox1DropDown(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure TreeView1Click(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);
    procedure N1Click(Sender: TObject);
    procedure N2Click(Sender: TObject);
    procedure N3Cl