unit1.pas

delphi6.0 的控件示例

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls, StdCtrls;

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    ListBox1: TListBox;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure ListBox1Enter(Sender: TObject);
  private
    MaxWidth:Integer;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  i:integer;
begin
  MaxWidth:=0;
  for i:=1 to 20 do
  begin
    ListBox1.Items.Add('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA');
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var i: integer; 
begin
  for i := 0 to ListBox1.Items.Count - 1 do
  if MaxWidth < ListBox1.Canvas.TextWidth(ListBox1.Items[i]) then
    MaxWidth := ListBox1.Canvas.TextWidth(ListBox1.Items[i]);
  SendMessage(ListBox1.Handle, LB_SETHORIZONTALEXTENT, MaxWidth+2, 0);
end;

procedure TForm1.ListBox1Enter(Sender: TObject);
{var i: integer;}
begin
{   在这里使用ListBox将自动出现水平滚动条 }
{  for i := 0 to ListBox1.Items.Count - 1 do
  if MaxWidth < ListBox1.Canvas.TextWidth(ListBox1.Items[i]) then
    MaxWidth := ListBox1.Canvas.TextWidth(ListBox1.Items[i]);
  SendMessage(ListBox1.Handle, LB_SETHORIZONTALEXTENT, MaxWidth+2, 0);}
end;

end.