如何将文件从一个用户传输到另一个用户。我正在使用 xmpp 协议进行连接，我尝试过以下代码进行连接。但是每次连接失败时我都会收到消息。
[TURNSocket setProxyCandidates:@[@"testserver-desktop"]];
XMPPJID *jid = [XMPPJID jidWithString:@"256122466@testserver-desktop"];
TURNSocket *turnSocket = [[TURNSocket alloc] initWithStream:[self xmppStream] toJID:jid];
[turnSockets addObject:turnSocket];
[turnSocket startWithDelegate:self delegateQueue:dispatch_get_main_queue()];
[turnSocket release];
// 委托 - (void)turnSocket:(TURNSocket *)sender didSucceed:(GCDAsyncSocket *)socket {
NSLog(@"TURN Connection succeeded!");
NSLog(@"You now have a socket that you can use to send/receive data to/from the other person.");
}
(void)turnSocketDidFail:(TURNSocket *)sender {
NSLog(@"TURN 连接失败！");
}
请让我如何在两个用户之间建立连接以进行文件传输。