func main() {
 client, err := DialHelloService("tcp", "localhost:1234")
 if err != nil {
 log.Fatal("dialing:", err)
 }
 var reply string
 err = client.Hello("hello", &reply)
 if err != nil {
 log.Fatal(err)
 }
 fmt.Println(reply) // 缺少这个打印
}