一直苦恼于找不到获取系统默认的UserAgent的方法，今天偶然想到一种方法，可实现效果

/// <summary>

/// 获取系统默认的UserAgent

/// uses SHDocVw, MSHTML;

/// </summary>

function GetUserAgent: string;

var

Doc: IHTMLDocument2;

win: IHTMLWindow2;

wb: TWebBrowser;

begin

Result := '';

try

wb := TWebBrowser.Create(nil);

try

wb.Navigate('about:blank');

while not wb.ReadyState = READYSTATE_COMPLETE do

Application.ProcessMessages;

Doc := IHTMLDocument2(wb.Document);

if not Assigned(Doc) then Exit;

win := Doc.parentWindow;

if Assigned(win) then

Result := win.clientInformation.userAgent;

finally

wb.Free;

end;

except

end;

end;

注：此方法为获取系统默认的UserAgent的方法，而不一定是系统默认IE浏览器的UserAgent，如需获取IE浏览器的UserAgent，可将Webbrowser对象改为IWebBrowser2或IShellWindows等接口即可