了解请求命令的 XML 结构至关重要.无论如何，您也可以通过这种方式向您发送命令

It is vital that u know the XML structure of the request command. In any case you can send you command in such a way too

 $message = "<root>"."\n";
 $message .= "<request>topUp</request>"."\n";
 $message .= "</root>"."\n";
 fputs ($fp, $message );

但是除非您发送已定义的请求结构，否则您可能无法获得想要的结果.

But unless you send your request structure defined you might not get the result you want.