socket on iOS

you can use CFStream or NSStream which use Object-C

@ViewController.h

#include <sys/socket.h>

#include <netinet/in.h>

#define PORT 9000

@interface ViewController : UIViewController<NSStreamDelegate>

{

    int flag ; //動作標志 0為傳送 1為接收

}

@property (nonatomic, retain) NSInputStream *inputStream;

@property (nonatomic, retain) NSOutputStream *outputStream;

@property (weak, nonatomic) IBOutlet UILabel *message;

- (IBAction)sendData:(id)sender;

- (IBAction)receiveData:(id)sender;

@end

define input & output stream

- (void)initNetworkCommunication

{

    

    CFReadStreamRef readStream;

    CFWriteStreamRef writeStream;

    CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)@"192.168.0.100", PORT, &readStream, &writeStream);

    

    _inputStream = (__bridge_transfer NSInputStream *)readStream;

    _outputStream = (__bridge_transfer NSOutputStream

                     *)writeStream;

    [_inputStream setDelegate:self];

    [_outputStream setDelegate:self];

    [_inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop]

                            forMode:NSDefaultRunLoopMode];

    [_outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop]

                             forMode:NSDefaultRunLoopMode];

    [_inputStream open];

    [_outputStream open];

    

}

initialize Network, set ip address & port number

-(void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {

    NSString *event;

    switch (streamEvent) {

        case NSStreamEventNone:

            event = @"NSStreamEventNone";

            break;

        case NSStreamEventOpenCompleted:

            event = @"NSStreamEventOpenCompleted";

            break;

        case NSStreamEventHasBytesAvailable:

            event = @"NSStreamEventHasBytesAvailable";

            if (flag ==1 && theStream == _inputStream) {

                NSMutableData *input = [[NSMutableData alloc] init];

                uint8_t buffer[1024];

                int len;

                while([_inputStream hasBytesAvailable])

                {

                    len = [_inputStream read:buffer maxLength:sizeof(buffer)];

                    if (len > 0)

                    {

                        [input appendBytes:buffer length:len];

                    }

                }

                NSString *resultstring = [[NSString alloc] initWithData:input encoding:NSUTF8StringEncoding];

                NSLog(@"接收:%@",resultstring);

                _message.text = resultstring;

            }

            break;

        case NSStreamEventHasSpaceAvailable:

            event = @"NSStreamEventHasSpaceAvailable";

            if (flag ==0 && theStream == _outputStream) {

                //輸出

                UInt8 buff[] = "Hello Server!";

                [_outputStream write:buff maxLength: strlen((const char*)buff)+1];

                 //必須關閉輸出流否則，伺服器端一直讀取不會停止，

                [_outputStream close];

            }

            break;

        case NSStreamEventErrorOccurred:

            event = @"NSStreamEventErrorOccurred";

            [self close];

            break;

        case NSStreamEventEndEncountered:

            event = @"NSStreamEventEndEncountered";

            NSLog(@"Error:%d:%@",[[theStream streamError] code], [[theStream streamError] localizedDescription]);

            break;

        default:

            [self close];

            event = @"Unknown";

            break;

    }

    NSLog(@"event------%@",event);

}

當有stream時，會呼叫此函數