THPDFPreflightPluginEvaluate Type

THPDFPreflightPluginEvaluate = reference to function(
  const Context: THPDFPreflightPluginContext;
  out PluginResult: THPDFPreflightPluginResult;
  out ErrorMessage: AnsiString): Boolean;

当求值无法安全完成时，返回带稳定错误消息的 False