Problems using udp to send input to fg

[RuiRui]

Hello, although I read a lot of posts about how to use udp socket to send inputs to FG, but I still can not succeed. Could you please have a look?
I want to set 'throttle' as 0.9
This is the udp client codes:

Code (client.c): Select all

#include<stdio.h>
#include<winsock2.h>
#pragma comment(lib,"ws2_32.lib")
#pragma warning(disable:4996)
int main(int argc, char * argv[])
{
WSADATA data;
SOCKET socketfd;
struct sockaddr_in my_addr;
char buf[80]="0.9";


if (WSAStartup(MAKEWORD(2, 2), &data) != 0)
{
return 0;

}
socketfd = socket(AF_INET, SOCK_DGRAM, 0);
if (socketfd<0)
{
return 0;
}
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(8000);
my_addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
while (1)
{
int ret=sendto(socketfd, buf, strlen(buf), 0, (struct sockaddr *)&my_addr, sizeof(my_addr));
printf("ret is:\n%d\n", ret);
}
closesocket(socketfd);
WSACleanup();
return 0;
}

This is XML file(sendsocket):

Code (sensockt.xml): Select all

<?xml version="1.0"?>
<PropertyList>
<generic>
<input>
<line_separator>newline</line_separator>
<var_separator>,</var_separator>

<chunk>
<node>/controls/engines/engine/throttle</node>
<name>throttle</name>
<type>float</type>
<format>%f</format>
</chunk>

</input>
</generic>
</PropertyList>

I want to change throttle.

And I run FG first, used
fgfs--generic=socket,in,1,localhost,8000,udp,sendsocket
then run the client codes.

But I see the property browser in FG, there is no change. But socket send successfully.
Is there anybody know reasons?