procedure TForm1.Button1Click(Sender: TObject);
var
i:integer;
begin
for i:=0 to listbox1.Items.Count-1 do
if listbox1.Items.Strings=trim(Edit1.text) then
begin
showmessage('输入数据重复！');
exit;
end;
listbox1.Items.Append(trim(Edit1.text));
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
if not myIsExist(Edit1.Text) then ListBox1.Items.Add(Edit1.Text);
end;
function TForm1.myIsExist(aStr: String): Boolean;
var
i : integer;
begin
ReSult := False;
for i :=0 to ListBox1.Items.Count-1 do
if ListBox1.Items.Strings=aStr then ReSult := True;
end;
