QTcpSocket::connectToHost

[yogeshgokul]

Hello All,

I am trying to connect using QTcpSocket::connectToHost. This is working fine when I provide host IP (tcpSocket->connectToHost("xx.xx.xx.xx".80)).

But not working when I provide host name (tcpSocket->connectToHost("www.xxx.com".80)).
It seems it not resolving host name.
What can I do ?

[yxmaomao]

from Qt's document, it should support host name,
Could you try : "At any point, the socket can emit error() to signal that an error occurred. "
to get detailed error information?

[yogeshgokul]

Its always giving same error. "host not found".

[yogeshgokul]

I found one more problem with QTcpSocket class.
When we set proxy settings in this class, we need to call QTcpSocket::setProxy(QNetworkProxy("HOST NAME", PORT));

But this is not working at all. Means its setting the proxy but not using that.
It means
case 1:
Proxy server is there("xyz",3128).
QTcpSocket soc;
soc.setProxy(QNetworkProxy("xyz", 3128));
soc.connectToHost("100.100.100.100", 80);

case 2:
Proxy server is not there.
QTcpSocket soc;
soc.connectToHost("100.100.100.100", 80);

case 3:
Proxy server is there("xyz",3128).
QTcpSocket soc;
soc.setProxy(QNetworkProxy("xyz", 3128));
soc.connectToHost("www.yahoo.com", 80);

case 4:
Proxy server is not there.
QTcpSocket soc;
soc.connectToHost("www.yahoo.com", 80);



In this scenario only case 2 will work.
Case 2 will only work because there is no proxy server and we provide IP address instead of host name in function connectToHost.



So there are 2 issues with TCP Socket.

1. Resolving host name e.g soc.connectToHost("www.yahoo.com", 80);
2. Use proxy settings done by e.g. soc.setProxy(QNetworkProxy("xyz", 3128));

[jacek]

Does it work if you specify the proxy's IP address instead of its name? It looks like name resolution doesn't work on your system.

[yogeshgokul]

I also thought that and tried already but no luck. I forget to mention that case here.

[lengshuang]

Today I encounter the same problem!if I use the host name,always the error:host not found!But when I use the IP address,such as :xx.xx.xx.xx,it work perfectly!I don‘t know why

[nish]

hey yogesh!! ... are u still stuck with the problem we faced at PSPL??? as far as i remember when we were coding SM2 and working on upload/download muhurta u faced the same problem...

remember PM told that we have hardcoded the website ip in fndef file ...

this remided me of old days... jeevan me chai gala sek kar peene ka maja he kuch aur tha..

[yogeshgokul]

Yes this is same problem, but now resolved in latest qt build 4.5.X. ha yaar wo din to mast hi the jab appan 3 din me apps bana ke fek dete the.. iski maka naka kar dete the

[nish]

mujhe to ab bhi lagta hai ki hum 3 din me app bana ke pani ka gilaas manager ke muh pe mar sakte hain

[nish]

aur jab wo apni aankhe mal raha hoga to kya kehna/karna chahiye?

[yogeshgokul]

uska haath aakho pe se hata ke, kheech ke lappad laga te hai,