unit3.~pas

《delphi 7.0_8.0课程设计与系统开发案例》随书代码

unit Unit3;

interface

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

type
  TForm3 = class(TForm)
    Label1: TLabel;
    Table1: TTable;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    DBNavigator1: TDBNavigator;
    StaticText1: TStaticText;
    ComboBox1: TComboBox;
    Label2: TLabel;
    Label3: TLabel;
    ComboBox2: TComboBox;
    Label4: TLabel;
    ComboBox3: TComboBox;
    BitBtn1: TBitBtn;
    Memo2: TMemo;
    memo1: TMemo;
    ComboBox4: TComboBox;
    Label5: TLabel;
    procedure ComboBox1Click(Sender: TObject);
    procedure ComboBox2Click(Sender: TObject);
    procedure ComboBox3Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure ComboBox4Click(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form3: TForm3;

implementation

{$R *.dfm}

procedure TForm3.ComboBox1Click(Sender: TObject);
begin
memo1.text:=memo1.text+ComboBox1.Text;
end;

procedure TForm3.ComboBox2Click(Sender: TObject);
begin
memo1.text:=memo1.text+ComboBox2.Text;
end;

procedure TForm3.ComboBox3Click(Sender: TObject);
begin
memo1.text:=memo1.text+ComboBox3.Text;
end;

procedure TForm3.FormCreate(Sender: TObject);
var
i:integer;
begin
 for i:=0 to table1.fieldcount-1 do
 ComBobox4.items.add(table1.fields[i].fieldname);
end;

procedure TForm3.ComboBox4Click(Sender: TObject);
begin
MEMO1.Text:=MEMO1.Text+ ComboBox4.Text;
end;

procedure TForm3.BitBtn1Click(Sender: TObject);
var
sum1:real;
s:string;
bookmark1:tbookmark;
begin
sum1:=0.00;
bookmark1:=table1.getbookmark;
table1.disablecontrols;
table1.first;
while not table1.eof do
begin
sum1:=sum1+table1.fieldbyname('yjf').value;
table1.Next;
end;
table1.gotobookmark(bookmark1);
table1.FreeBookmark(bookmark1);
table1.EnableControls;
str(sum1:8:2,s);
memo2.text:=s;

end;

end.