IOS的网络通信的方法

ios设备的网络通信的方法，有如下两个大类：

1、使用socket的方式进行通信。

2、使用asynsocket类库进行通信。

两种方法当中，我觉得asynsocket更好，因为是别人已经封装好的类库，比较稳定。但是对于直接使用socket的通信方法我倒是觉得很灵活。因为控制都是自己在做的事情。

先列举集中不同的使用方法：

1、直接使用socket的方式。

以 TCP为利，对于TCP来说，是要区分服务端和客户端的。服务端：通常的方法是服务端启动后监听，是否有客户端连接，如果有连接，则建立与客户端的通信。客户端的方法通常是连接服务端，当连接成功之后，就希望发送数据了。

客户端：

CFSocketContext sockContext ;

CFSocketRef  cfsock ;

sockContext.info =self;

sockContext.copyDescription =0;

cfsock =CFSocketCreate(kCFAllocatorDefault,

PF_INET,

SOCK_STREAM,

IPPROTO_TCP,

kCFSocketConnectCallBack,

MyCallBack,

&sockContext

);

// 这个地方是个关键的地方，就是建立一个ip地址，然后使的客户端可以向服务端发起连接。

NSString  *strAddress = @"192.168.1.1";

if (cfsock !=nil) {

struct sockaddr_in addr4; 

memset(&addr4,0,sizeof(addr4));

addr4.sin_len = sizeof(addr4);

addr4.sin_family =AF_INET;

addr4.sin_port = htons(1230);

addr4.sin_addr.s_addr =inet_addr( [strAddress UTF8String] );

CFDataRef address =CFDataCreate(kCFAllocatorDefault, (UInt8*)&addr4,sizeof(addr4));

CFSocketConnectToAddress(cfsock, address, -1);

}

// 发起连接之后，需要将runloop的过程，也就是消息的过程加入到当前线程当中。这样当有事件发生时，会调用对应的方法。

CFRunLoopRef crun =CFRunLoopGetCurrent();//CFRunLoopGetMain();

CFRunLoopSourceRef source =CFSocketCreateRunLoopSource(kCFAllocatorDefault,cfsock, 0);

CFRunLoopAddSource(crun, source,kCFRunLoopCommonModes);

CFRelease(source);

回调函数：当连接成功之后的处理如下：

static void MyCallBack (

CFSocketRef          s,

CFSocketCallBackType callbackType,

CFDataRef    address,

constvoid   *data,

void         *info

)

{

if (data!=NULL) {

NSLog(@"传输失败!");

}

SocketTestAppDelegate *client = (SocketTestAppDelegate*)info;

[client performSelectoInBackground:@selector(readstream)withObject:nil];

}

-(void) readstream

{

char buffer[1024];

NSAutoreleasePool *pool = [[NSAutoreleasePoolalloc] init];

while (recv(CFSocketGetNative(cfsock),buffer,sizeof(buffer),0)) {

}

[pool release];

}

//  如果希望直接向服务器写内容的话，采用如下的方法。

-(void) sendstream

{

NSString * stringtosend = @"hello everyone";

const char *data = [stringtosendUTF8String];

send(CFSocketGetNative(cfsock),data,strlen(data)+1,0);

}

服务器端的程序：

CFSocketRef socketserver;

int setupSocket()

{

socketserver =CFSocketCreate(kCFAllocatorDefault,PF_INET,SOCK_STREAM,IPPROTO_TCP,kCFSocketAcceptCallBack,myaccept,NULL);

int optval =1;

setsockopt(CFSocketGetNative(socketserver),SOL_SOCKET, SO_REUSEADDR, (void*)&optval,sizeof(optval));

struct sockaddr_in addr4;

memset(&addr4,0,sizeof(addr4));

addr4.sin_len = sizeof(addr4);

addr4.sin_family = AF_INET;

addr4.sin_port = htons(10);

addr4.sin_addr.s_addr=htonl(INADDR_ANY);

CFDataRef  address = CFDataCreate(kCFAllocatorDefault, (UInt8*)&addr4,sizeof(addr4));

CFSocketSetAddress(socketserver, address);

CFRunLoopRef cfRunloop =CFRunLoopGetCurrent();

CFRunLoopSourceRef source =CFSocketCreateRunLoopSource(kCFAllocatorDefault,socketserver, 0);

CFRunLoopAddSource(cfRunloop, source,kCFRunLoopCommonModes);

CFRelease(source);

}

//服务端的socket建立之后，就需要接受client的连接，因此建立连接的回调函数。

static void myaccept (

CFSocketRef          s,

CFSocketCallBackType callbackType,

CFDataRef    address,

constvoid   *data,

void         *info

)

{

if (callbackType ==kCFSocketAcceptCallBack) {

// 如果对端连接成功的话，是可以获取对端的名称和socket的。

CFSocketNativeHandle nativesockethandle = *(CFSocketNativeHandle*)data;

uint8_t name[100];

socklen_t namelen =100;

getpeername(nativesockethandle, (struct sockaddr *)name, &namelen);

//除此以外，更重要的是获取输入流 和 输出流，

CFReadStreamRef iStream;

CFWriteStreamRef oStream;

// 创建一个可读写的socket连接

CFStreamCreatePairWithSocket(kCFAllocatorDefault, nativesockethandle, &iStream, &oStream);

CFStreamClientContextstreamcontext={

0,NULL,NULL,NULL

};

// 注册两种事件！

CFReadStreamSetClient(iStream,kCFStreamEventHasBytesAvailable, readStream, &streamcontext);

CFReadStreamSetClient(iStream,kCFStreamEventCanAcceptBytes, writeStream, &streamcontext);

//加入到循环当中！

CFReadStreamScheduleWithRunLoop(iStream,CFRunLoopGetCurrent(),kCFRunLoopCommonModes);

CFWriteStreamScheduleWithRunLoop(oStream,CFRunLoopGetCurrent(),kCFRunLoopCommonModes);

CFReadStreamOpen(iStream);

CFWriteStreamOpen(oStream);

}

}

void readStream(CFReadStreamRef stream,CFStreamEventType eventType,void *clientCallBackInfo) {

    UInt8 buff[255];

    CFReadStreamRead(stream, buff, 255);

    printf("received: %s", buff);

}

void writeStream (CFWriteStreamRef stream,CFStreamEventType eventType, void *clientCallBackInfo) {

   // outputStream = stream;

   char *str = "nihao";

    CFWriteStreamWrite(outputStream, str, strlen(line) + 1);

}

另一种方法是使用NSStream的方式构建客户端，然后发送和接受内容。

-(void)startClient

{

    host = [NSHosthostWithAddress:@"192.168.201.24"];//hostWithName:@"www.apple.com"];

    [NSStreamgetStreamsToHost:host port:4242 inputStream:&inStream outputStream:&outStream];

     

    if((inStream == nil) || (outStream == nil))

    {

        NSLog(@"Error: Failed to create streams!") ;

        [selfrelease];

    }

}

 

- (void)stream:(NSStream*)aStream handleEvent:(NSStreamEvent)eventCode

{

    switch(eventCode) {

        caseNSStreamEventHasBytesAvailable:

        {

            NSMutableData*input = [[NSMutableDataalloc] init];

            uint8_t buffer[1024];

            intlen;

            while([inStream hasBytesAvailable])

            {

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

                if(len > 0)

                {

                    [input appendBytes:buffer length:len];

                }

            }

            self._resultdata = input;

            self._resultstring = [[NSStringalloc] initWithData:input encoding:NSUTF8StringEncoding];

            [input release];

            break;

        }

        caseNSStreamEventEndEncountered:

            [selfcloseStream];

            break;

        caseNSStreamEventHasSpaceAvailable:

        caseNSStreamEventErrorOccurred:

        {

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

        }

        caseNSStreamEventOpenCompleted:

        caseNSStreamEventNone:

        default:

            break;

    }

}

 

-(void)closeStream{

    [inStream close];

    [outStream close];

    [inStream removeFromRunLoop:[NSRunLoopcurrentRunLoop] forMode:NSDefaultRunLoopMode];

    [outStream removeFromRunLoop:[NSRunLoopcurrentRunLoop] forMode:NSDefaultRunLoopMode];

    [inStream setDelegate:nil];

    [outStream setDelegate:nil];

    [inStream release];

    [outStream release];

    inStream = nil;

    outStream = nil;

}

 

-(void)openStream{

    [inStream retain];

    [outStream retain];

    [inStream setProperty:NSStreamSocketSecurityLevelSSLv3forKey:NSStreamSocketSecurityLevelKey];

    [outStream setProperty:NSStreamSocketSecurityLevelSSLv3forKey:NSStreamSocketSecurityLevelKey];

    NSMutableDictionary* sslSettings;

    sslSettings = [NSMutableDictionarydictionaryWithObjectsAndKeys:(id)kCFBooleanFalse,kCFStreamSSLValidatesCertificateChain,kCFBooleanFalse,kCFStreamSSLIsServer,nil];

    CFWriteStreamSetProperty((CFWriteStreamRef)outStream, kCFStreamPropertySSLSettings, sslSettings);

    [inStream setDelegate:self];

    [outStream setDelegate:self];

    [inStream scheduleInRunLoop:[NSRunLoopcurrentRunLoop] forMode:NSDefaultRunLoopMode];

    [outStream scheduleInRunLoop:[NSRunLoopcurrentRunLoop] forMode:NSDefaultRunLoopMode];

    [inStream open];

    [outStream open];

}

 

-(int)writeString: (NSString*) string

{

    NSData*messageAsData = [string dataUsingEncoding:NSASCIIStringEncoding];

    return[outStream write: (c*****t uint8_t *) [messageAsData bytes] maxLength: [messageAsData length]];

}

 

-(int)writeBytes: (char*) buffer length: (unsigned int) len

{

    return[outStream write: (c*****t uint8_t *) buffer maxLength: len];

}

@end