无法使用GCDAsyncSocket从服务器读取数据

Question

I tried to connect to the server and send some information to the server(like username, password..), and the server send me back the ID (string type). The problem is I can not get the ID. Could anyone help me? I am beginner in IOS coding. Thanks.

Here is the codes:

1. After I click the button, it will call my own function to get serverIP which is a string and Port which is a int.

2. Then that function will call this function to connect the server:

    (void)logInCheck { asyncSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()]; NSError *error = nil; uint16_t port = serverPort; if (![asyncSocket connectToHost:serverIP onPort:port error:&error]) { DDLogError(@"Unable to connect to due to invalid configuration: %@", error); } else { DDLogVerbose(@"Connecting..."); [self passDataToServer]; } } //DataPassToServer is a NSString that hold my data (void)passDataToServer { NSData *requestData = [DataPassToServer dataUsingEncoding:NSUTF8StringEncoding]; [asyncSocket writeData:requestData withTimeout:-1.0 tag:0]; [asyncSocket readDataWithTimeout:-1 tag:0]; } //this function call successfully -(void)socket:(GCDAsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port { DDLogVerbose(@"socket:didConnectToHost:%@ port:%hu", host, port); } //this function call successfully (void)socket:(GCDAsyncSocket *)sock didWriteDataWithTag:(long)tag { DDLogVerbose(@"socket:didWriteDataWithTag:"); } //This function does not run !!! Nothing print out. (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag { DDLogVerbose(@"socket:didReadData:withTag:"); NSString *response = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]; NSLog(@"ID = %@",response); [asyncSocket readDataWithTimeout:-1 tag:0]; } 

Answer 1

I don't know about your server implementation but, most implementations would read up to the first newline character before processing the request.

So make sure that your [DataPassToServer dataUsingEncoding:NSUTF8StringEncoding] includes a newline character ( "\\n" ) at the end.

Your code looks fine and works for me.