原文 http://zwkufo.blog.163.com/blog/static/2588251201072581947474/

[Code]
function SuiteRemovedAlert2: boolean;
external 'SuiteRemovedAlert@{app}\SuiteRemovedAlert.dll stdcall delayload uninstallonly';

function InitializeUninstall(): boolean;
var Isbl: boolean;         //声明变量
    sDir: string;
    sFind: string;
begin
  sDir:=ExpandConstant('{app}'); //返回用户选择的安装文件夹
  sFind:=FileSearch('SuiteRemovedAlert.dll',sDir); //判断文件是否存在
  if sFind='' then begin
    result:=True;
  end else begin
    result:=SuiteRemovedAlert2();
    UnloadDLL(ExpandConstant('{app}\SuiteRemovedAlert.dll'));
  end;
end;