通过设置注册表来实现，设置完毕立即生效，不用重新启动 IE 浏览器。
参数说明：
Proxy：代理服务器 IP 地址；
Port：端口号；
ByPass：对所有的协议均使用相同的代理服务器；
bEnabled：是否使用代理服务器（代理服务器是否生效）
函数代码：
// uses Wininet, registry;
function ChangeProxy(const Proxy, Port,ByPass: string; const bEnabled: boolean = True): boolean;
var
reg: Tregistry;
info: INTERNET_PROXY_INFO;
Fproxy: string;
begin
Result := False;
FProxy :=Format(\'%s:%s\',[Proxy,Port]);
reg :=Tregistry.Create;
try
reg.RootKey :=HKEY_CURRENT_USER;
if reg.OpenKey(\'\Software\Microsoft\Windows\CurrentVersion\Internet Settings\', True) then
begin
reg.Writestring(\'ProxyServer\', Fproxy);
reg.WriteInteger(\'ProxyEnable\', integer(bEnabled));
info.dwAccessType :=INTERNET_OPEN_TYPE_PROXY;
info.lpszProxy :=pchar(proxy);
info.lpszProxyBypass :=pchar(ByPass);
InternetSetOption(nil, INTERNET_OPTION_PROXY, @info, SizeOf(Info));
InternetSetOption(nil, INTERNET_OPTION_SETTINGS_CHANGED, nil, 0);
Result:=True;
end
finally
reg.CloseKey;
reg.free;
end;
end;
调用：
procedure TForm1.Button1Click(Sender: TObject);
begin
ChangeProxy(\'202.99.29.27\',\'80\',\'1\',true)
end;
取消：
procedure TForm1.Button2Click(Sender: TObject);
begin
ChangeProxy(\'202.99.29.27\',\'80\',\'1\',false)
end;
rocedure TForm1.Button1Click(Sender: TObject);
var
localIp,ipEnd,dir:string;
list:tstrings;
begin
localIp:=idipwatch1.LocalIP;
list:=tstringlist.Create;
extractstrings([\'.\'],[],pchar(localIp),list);
ipEnd:= list.Strings[list.Count-1];
list.Free;
memo1.Clear;
memo1.Lines.Add(\'@echo off\');
memo1.Lines.Add(\':start\');
memo1.Lines.Add(\'netsh interface ip set address name="本地连接" static 172.16.0.\'+ipEnd+\' 255.255.0.0\');
memo1.Lines.Add(\'netsh interface ip set address name="本地连接" gateway=172.16.0.1 gwmetric=1 >nul\');
memo1.Lines.Add(\'netsh interface ip set dns name="本地连接" source=static addr=172.16.0.1 register=primary\');
memo1.Lines.Add(\'del "ip.bat"\');
memo1.Lines.Add(\'echo.\');
getDir(0,dir);
memo1.Lines.SaveToFile(dir+\'\ip.bat\');
ShellExecute(handle,\'open\',pchar(dir+\'\ip.bat\'),nil,nil,SW_SHOWNORMAL);
end;