简易浏览器(delphi源码)

非常简单的一个小程序~
不过有一个BUG,贴出源码,大家帮忙一起研究下!
简易浏览器源码:
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls, ComCtrls, OleCtrls, SHDocVw, jpeg,
WinSkinData;

type
TForm1 = class(TForm)
  Button1: TButton;
  Button2: TButton;
  Button3: TButton;
  Button4: TButton;
  Image1: TImage;
  WebBrowser1: TWebBrowser;
  StatusBar1: TStatusBar;
  Label1: TLabel;
  SkinData1: TSkinData;
  Button5: TButton;
  Button6: TButton;
  Button7: TButton;
  Button8: TButton;
  Button9: TButton;
  Button10: TButton;
  Button11: TButton;
  Button12: TButton;
  Button13: TButton;
  Button14: TButton;
  ComboBox1: TComboBox;
  procedure Button1Click(Sender: TObject);
  procedure Button2Click(Sender: TObject);
  procedure Button3Click(Sender: TObject);
  procedure Button4Click(Sender: TObject);
  procedure Button5Click(Sender: TObject);
  procedure Button6Click(Sender: TObject);
  procedure Button10Click(Sender: TObject);
  procedure Button7Click(Sender: TObject);
  procedure Button8Click(Sender: TObject);
  procedure Button9Click(Sender: TObject);
  procedure Button11Click(Sender: TObject);
  procedure Button12Click(Sender: TObject);
  procedure Button13Click(Sender: TObject);
  procedure Button14Click(Sender: TObject);
  procedure WebBrowser1NavigateComplete2(Sender: TObject;
    const pDisp: IDispatch; var URL: OleVariant);
private
  { Private declarations }
public
  { Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
webbrowser1.Navigate(combobox1.Text);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
webbrowser1.GoForward; //前进
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
webbrowser1.GoBack;   //后退
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
webbrowser1.GoHome; 首页
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
webbrowser1.Stop; //停止
end;

procedure TForm1.Button6Click(Sender: TObject);
begin
webbrowser1.refresh; //刷新
end;

procedure TForm1.Button10Click(Sender: TObject);
begin
webbrowser1.GoSearch; //搜索
end;

procedure TForm1.Button7Click(Sender: TObject);
begin
try
webbrowser1.ExecWB(shdocvw.OLECMDID_COPY,
shdocvw.OLECMDEXECOPT_DONTPROMPTUSER);
except
showmessage('复制操作错误');
end;
end;

procedure TForm1.Button8Click(Sender: TObject);
begin
try
webbrowser1.ExecWB(shdocvw.OLECMDID_PASTE,
shdocvw.OLECMDEXECOPT_DONTPROMPTUSER);
except
showmessage('粘贴操作错误');
end;
end;

procedure TForm1.Button9Click(Sender: TObject);
begin
try
webbrowser1.ExecWB(shdocvw.OLECMDID_CUT,
shdocvw.OLECMDEXECOPT_DONTPROMPTUSER);
except
showmessage('剪切操作错误');
end;
end;

procedure TForm1.Button11Click(Sender: TObject);
begin
try
webbrowser1.ExecWB(shdocvw.OLECMDID_SELECTALL,
shdocvw.OLECMDEXECOPT_DONTPROMPTUSER);
except
showmessage('全选操作错误');
end;
end;

procedure TForm1.Button12Click(Sender: TObject);
begin
try
webbrowser1.ExecWB(shdocvw.OLECMDID_Delete,
shdocvw.OLECMDEXECOPT_DONTPROMPTUSER);
except
showmessage('删除操作错误');
end;
end;

procedure TForm1.Button13Click(Sender: TObject);
begin
try
webbrowser1.ExecWB(shdocvw.OLECMDID_print,
shdocvw.OLECMDEXECOPT_DONTPROMPTUSER);
except
showmessage('打印操作错误');
end;
end;

procedure TForm1.Button14Click(Sender: TObject);
begin
try
webbrowser1.ExecWB(shdocvw.OLECMDID_PROPERTIES,
shdocvw.OLECMDEXECOPT_DONTPROMPTUSER);
except
showmessage('页面设置错误');
end;
end;
procedure TForm1.WebBrowser1NavigateComplete2(Sender: TObject;
const pDisp: IDispatch; var URL: OleVariant);
begin
combobox1.Text:=webbrowser1.LocationURL;
if
combobox1.Items.IndexOf(webbrowser1.LocationURL)=-1 then
combobox1.Items.Add(webbrowser1.LocationURL);
end;
end.