unit6.pas

本系统为学生管理系统,可实现选课和退选

unit Unit6;

interface

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

type
  TForm6 = class(TForm)
    Table1: TTable;
    SavePictureDialog1: TSavePictureDialog;
    Button1: TButton;
    Button2: TButton;
    Memo1: TMemo;
    ListBox1: TListBox;
    ListBox2: TListBox;
    ComboBox1: TComboBox;
    ComboBox2: TComboBox;
    procedure FormCreate(Sender: TObject);
   // procedure BitBtn2Click(Sender: TObject);
  //  procedure BitBtn1Click(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);
    procedure ComboBox2Change(Sender: TObject);
    procedure ListBox1Click(Sender: TObject);
    procedure ListBox2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form6: TForm6;
  str4:string;
  k: integer;
implementation

uses Unit5;

{$R *.dfm}

procedure TForm6.FormCreate(Sender: TObject);
var i,j:integer;
begin

        k:=0;
        combobox1.Clear;
        combobox2.Clear;
        memo1.Text:='';
        for i:=0 to Form5.listbox2.Count-1 do
        begin
                combobox1.Items.Add(Form5.listbox2.Items[i]);
                combobox2.Items.Add(Form5.listbox2.Items[i]);
         end;
         button1.Enabled:=false;
end;

{procedure TForm6.BitBtn2Click(Sender: TObject);

begin

//form6.close;
end;}

{procedure TForm6.BitBtn1Click(Sender: TObject);

 (listbox1.ItemIndex=-1) and (listbox2.ItemIndex=-1) then
        showmessage('请先选择正确项')

else
begin
if (listbox1.Items[listbox1.itemindex] = listbox2.Items[listbox2.itemindex]) and(combobox1.Text<>combobox2.Text) then
begin

        first:=combobox1.Text+'.'+listbox1.Items[listbox1.itemindex];
      second:=combobox2.Text+'.'+listbox2.Items[listbox2.itemindex];
        if memo1.text='' then
                memo1.Text:=first+'='+second
        else
                memo1.Text:=memo1.text+' '+'and'+' '+first+'='+second;



end
else
        showmessage('关联字段不对');
end;

showmessage(str4);
str4:=memo1.text;
end; }

procedure TForm6.ComboBox1Change(Sender: TObject);
var j:integer;
begin
        table1.Active:=false;
        table1.TableName:='';
        listbox1.Clear;
        table1.TableName:=combobox1.text;
         table1.Active:=true;
         for j:=0 to table1.FieldCount-1 do
                listbox1.Items.Add(table1.Fields[j].FieldName);

end;

procedure TForm6.ComboBox2Change(Sender: TObject);
var j:integer;
begin
        table1.Active:=false;
        table1.TableName:='';
        listbox2.Clear;
        table1.TableName:=combobox2.text;
            table1.Active:=true;
         for j:=0 to table1.FieldCount-1 do
          listbox2.Items.Add(table1.Fields[j].FieldName);

end;


procedure TForm6.ListBox1Click(Sender: TObject);
begin
       button1.Enabled:=true;
end;

procedure TForm6.ListBox2Click(Sender: TObject);
begin
      button1.Enabled:=true;
end;

procedure TForm6.Button1Click(Sender: TObject);
var s1,s2:string;
begin
 if (listbox1.ItemIndex=-1) and (listbox2.ItemIndex=-1) then
        showmessage('请先选择正确项')

else
begin
if (listbox1.Items[listbox1.itemindex] = listbox2.Items[listbox2.itemindex]) and(combobox1.Text<>combobox2.Text) then
begin

        s1:=combobox1.Text+'.'+listbox1.Items[listbox1.itemindex];
      s2:=combobox2.Text+'.'+listbox2.Items[listbox2.itemindex];
        if memo1.text='' then
                memo1.Text:=s1+'='+s2
        else
                memo1.Text:=memo1.text+' '+'and'+' '+s1+'='+s2;



end
else
        showmessage('关联字段不对');
end;

//showmessage(str4);
//str4:=memo1.text;

end;

procedure TForm6.Button2Click(Sender: TObject);
begin
form6.close;
end;

end.