iOS_SN_Socket - AsyncSocket

转载文章，原地址：http://yimouleng.com/2015/02/04/Socket-AsyncSocket/

一、前言

公司的项目用到了Socket编程，之前在学习的过程当中，用到的更多的还是http请求的方式。但是既然用到了就必须学习一下，所以就在网上找一些例子，然后想自己写一个demo。可是发现很多写iOS Socket的博客并没有很详细的说明，也可能是大神们觉得其他东西都浅显易懂。

自己专研了一下，将自己的一些理解总结出来，一方面整理自己的学习思路，另一方面，为一些和我有同样困惑的小伙伴们，稍做指引。

二、AsyncSocket介绍

1??iOS中Socket编程的方式有哪些？

－BSD Socket

BSD Socket 是UNIX系统中通用的网络接口，它不仅支持各种不同的网络类型，而且也是一种内部进程之间的通信机制。而iOS系统其实本质就是UNIX，所以可以用，但是比较复杂。

－CFSocket

CFSocket是苹果提供给我们的使用Socket的方式，但是用起来还是会不太顺手。当然想使用的话，可以细细研究一下。

－AsyncSocket

这次博客的主讲内容，也是我们在开发项目中经常会用到的。

2??为什么选择AsyncSocket？

iphone的CFNetwork编程比较艰深。使用AsyncSocket开源库来开发相对较简单，帮助我们封装了很多东西。

三、AsyncSocket详解

1??说明

在我们开发当中，我们主要的任务是开发客户端。所以详解里主要将客户端的整个连接建立过程，以及在说明时候回调哪些函数。在后面的示例代码中，也会给出服务器端的简单开发。

2??过程详解

1.建立连接

- (int)connectServer:(NSString *)hostIP port:(int)hostPort

2.连接成功后，会回调的函数

- (void)onSocket:(AsyncSocket )sock didConnectToHost:(NSString )host port:(UInt16)port

3.发送数据

- (void)writeData:(NSData *)data withTimeout:(NSTimeInterval)timeout tag:(long)tag;

4.接受数据

-(void)onSocket:(AsyncSocket )sock didReadData:(NSData )data withTag:(long)tag

5.断开连接

- (void)onSocket:(AsyncSocket )sock willDisconnectWithError:(NSError )err

- (void)onSocketDidDisconnect:(AsyncSocket *)sock

主要就是上述的几个方法，只是说在真正开发当中，很可能我们在收发数据的时候，我们收发的数据并不仅仅是一个字符串包装成NSData即可，我们很可能会发送结构体等类型，这个时候我们就需要和服务器端的人员协作来开发：定义怎样的结构体。

四、AsyncSocket示例

客户端代码

#import “ViewController.h“

#define SRV_CONNECTED 0#define SRV_CONNECT_SUC 1#define SRV_CONNECT_FAIL 2#define HOST_IP @”192.168.83.40”#define HOST_PORT 8008

@interface ViewController (){    NSString _content;}-(int) connectServer: (NSString ) hostIP port:(int) hostPort;-(void)showMessage:(NSString ) msg;@end

@implementation ViewController

@synthesize clientSocket,tbInputMsg,lblOutputMsg;

#pragma mark - view lifecycle- (void)viewDidLoad{    [super viewDidLoad];

    [self connectServer:HOST_IP port:HOST_PORT];}- (void)viewDidUnload{    [super viewDidUnload];    [clientSocket release], clientSocket = nil;    [tbInputMsg release], tbInputMsg = nil;    [lblOutputMsg release], lblOutputMsg = nil;}

- (int)connectServer:(NSString )hostIP port:(int)hostPort{    if (clientSocket == nil)    {        // 在需要联接地方使用connectToHost联接服务器        clientSocket = [[AsyncSocket alloc] initWithDelegate:self];        NSError err = nil;        if (![clientSocket connectToHost:hostIP onPort:hostPort error:&err])        {            NSLog(@”Error %d:%@“, err.code, [err localizedDescription]);

            UIAlertView alert = [[UIAlertView alloc] initWithTitle:[@”Connection failed to host“ stringByAppendingString:hostIP] message:[NSString stringWithFormat:@”%d:%@“,err.code,err.localizedDescription] delegate:self cancelButtonTitle:@”OK“ otherButtonTitles:nil];            [alert show];            [alert release];            return SRV_CONNECT_FAIL;        } else {            NSLog(@”Connected!“);            return SRV_CONNECT_SUC;        }    }    else {        return SRV_CONNECTED;    }}

#pragma mark - IBAction// 发送数据- (IBAction) sendMsg:(id)sender{    NSString inputMsgStr = tbInputMsg.text;    NSString  content = [inputMsgStr stringByAppendingString:@”\r\n“];    NSLog(@”%@“,content);    NSData data = [content dataUsingEncoding:NSUTF8StringEncoding];    // NSData data = [content dataUsingEncoding:NSISOLatin1StringEncoding];    [clientSocket writeData:data withTimeout:-1 tag:0];}// 连接/重新连接- (IBAction) reconnect:(id)sender{    int stat = [self connectServer:HOST_IP port:HOST_PORT];    switch (stat) {        case SRV_CONNECT_SUC:            [self showMessage:@”connect success“];            break;        case SRV_CONNECTED:            [self showMessage:@”It’s connected,don’t agian“];            break;        default:            break;    }}- (void)showMessage:(NSString )msg{    UIAlertView  alert = [[UIAlertView alloc]initWithTitle:@”Alert!“                                                    message:msg                                                   delegate:nil                                          cancelButtonTitle:@”OK“                                          otherButtonTitles:nil];    [alert show];    [alert release];}- (IBAction)textFieldDoneEditing:(id)sender{    [tbInputMsg resignFirstResponder];}- (IBAction)backgroundTouch:(id)sender{    [tbInputMsg resignFirstResponder];}

#pragma mark socket delegate- (void)onSocket:(AsyncSocket )sock didConnectToHost:(NSString )host port:(UInt16)port{    [clientSocket readDataWithTimeout:-1 tag:0];}

- (void)onSocket:(AsyncSocket )sock willDisconnectWithError:(NSError )err{    NSLog(@”Error“);}

- (void)onSocketDidDisconnect:(AsyncSocket )sock{    NSString msg = @”Sorry this connect is failure“;    [self showMessage:msg];    [msg release];    clientSocket = nil;}

- (void)onSocketDidSecure:(AsyncSocket )sock{}

// 接收到数据（可以通过tag区分）-(void)onSocket:(AsyncSocket )sock didReadData:(NSData )data withTag:(long)tag{    NSString aStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];    _content = lblOutputMsg.text;    NSLog(@”Hava received datas is :%@“,aStr);    NSString newStr = [NSString stringWithFormat:@”\n%@“, aStr];    lblOutputMsg.text = [_content stringByAppendingString:newStr];    [aStr release];    [clientSocket readDataWithTimeout:-1 tag:0];}

@end

服务器端代码

#import “SocketView.h“#import “AsyncSocket.h“

#define WELCOME_MSG  0#define ECHO_MSG     1

#define FORMAT(format, …) [NSString stringWithFormat:(format), ##VA_ARGS]

@interface SocketView (PrivateAPI)- (void)logError:(NSString )msg;- (void)logInfo:(NSString )msg;- (void)logMessage:(NSString )msg;@end

@implementation SocketView

// 初始化- (void)awakeFromNib{    listenSocket = [[AsyncSocket alloc] initWithDelegate:self];    [listenSocket setRunLoopModes:[NSArray arrayWithObject:NSRunLoopCommonModes]];

    connectedSockets = [[NSMutableArray alloc] initWithCapacity:1];    isRunning = NO;

    [logView setString:@””];    // [portField setString:@”8080”];}

- (IBAction)startStop:(id)sender{    if(!isRunning)    {        int port = [portField intValue];

        if(port < 0 || port > 65535)        {            port = 0; // 会随即取端口        }

        NSError error = nil;        if(![listenSocket acceptOnPort:port error:&error])        {            [self logError:FORMAT(@”Error starting server: %@“, error)];            return;        }

        [self logInfo:FORMAT(@”Echo server started on port %hu“, [listenSocket localPort])];        isRunning = YES;

        [portField setEnabled:NO];        [startStopButton setTitle:@”Stop“];    }    else    {        // Stop accepting connections        [listenSocket disconnect];

        // Stop any client connections        int i;        for(i = 0; i < [connectedSockets count]; i++)        {            // Call disconnect on the socket,            // which will invoke the onSocketDidDisconnect: method,            // which will remove the socket from the list.            [[connectedSockets objectAtIndex:i] disconnect];        }

        [self logInfo:@”Stopped Echo server“];        isRunning = false;

        [portField setEnabled:YES];        [startStopButton setTitle:@”Start“];    }}

- (void)scrollToBottom{    NSScrollView scrollView = [logView enclosingScrollView];    NSPoint newScrollOrigin;

    if ([[scrollView documentView] isFlipped])        newScrollOrigin = NSMakePoint(0.0, NSMaxY([[scrollView documentView] frame]));    else        newScrollOrigin = NSMakePoint(0.0, 0.0);

    [[scrollView documentView] scrollPoint:newScrollOrigin];}

- (void)logError:(NSString )msg{    NSString paragraph = [NSString stringWithFormat:@”%@\n“, msg];

    NSMutableDictionary attributes = [NSMutableDictionary dictionaryWithCapacity:1];    [attributes setObject:[NSColor redColor] forKey:NSForegroundColorAttributeName];

    NSAttributedString as = [[NSAttributedString alloc] initWithString:paragraph attributes:attributes];    [as autorelease];

    [[logView textStorage] appendAttributedString:as];    [self scrollToBottom];}

- (void)logInfo:(NSString )msg{    NSString paragraph = [NSString stringWithFormat:@”%@\n“, msg];

    NSMutableDictionary attributes = [NSMutableDictionary dictionaryWithCapacity:1];    [attributes setObject:[NSColor purpleColor] forKey:NSForegroundColorAttributeName];

    NSAttributedString as = [[NSAttributedString alloc] initWithString:paragraph attributes:attributes];    [as autorelease];

    [[logView textStorage] appendAttributedString:as];    [self scrollToBottom];}

- (void)logMessage:(NSString )msg{    NSString paragraph = [NSString stringWithFormat:@”%@\n“, msg];

    NSMutableDictionary attributes = [NSMutableDictionary dictionaryWithCapacity:1];    [attributes setObject:[NSColor blackColor] forKey:NSForegroundColorAttributeName];

    NSAttributedString as = [[NSAttributedString alloc] initWithString:paragraph attributes:attributes];    [as autorelease];

    [[logView textStorage] appendAttributedString:as];    [self scrollToBottom];}

- (void)onSocket:(AsyncSocket )sock didAcceptNewSocket:(AsyncSocket )newSocket{    [connectedSockets addObject:newSocket];}

// 客户连接成功！- (void)onSocket:(AsyncSocket )sock didConnectToHost:(NSString )host port:(UInt16)port{    [self logInfo:FORMAT(@”Accepted client %@:%hu“, host, port)];

    NSString welcomeMsg = @”恭喜您,已经通过scoket连接上服务器!“;    NSData welcomeData = [welcomeMsg dataUsingEncoding:NSUTF8StringEncoding];

    [sock writeData:welcomeData withTimeout:-1 tag:WELCOME_MSG];

    // We could call readDataToData:withTimeout:tag: here - that would be perfectly fine.    // If we did this, we’d want to add a check in onSocket:didWriteDataWithTag: and only    // queue another read if tag != WELCOME_MSG.}

- (void)onSocket:(AsyncSocket )sock didWriteDataWithTag:(long)tag{   [sock readDataToData:[AsyncSocket CRLFData] withTimeout:-1 tag:0];}// 接收到数据- (void)onSocket:(AsyncSocket )sock didReadData:(NSData )data withTag:(long)tag{    NSData strData = [data subdataWithRange:NSMakeRange(0, [data length] - 2)];    NSString recvMsg = [[[NSString alloc] initWithData:strData encoding:NSUTF8StringEncoding] autorelease];    if(recvMsg)    {        [self logMessage:recvMsg];    }    else    {        [self logError:@”Error converting received data into UTF-8 String“];    }    NSString backStr = nil;    for (AsyncSocket socket in connectedSockets) {        if ([sock isEqualTo:socket]) {            backStr = [NSString stringWithFormat:@”我说: %@“,recvMsg];        } else {            backStr = [NSString stringWithFormat:@”他说: %@“,recvMsg];        }    }

    // 回发数据    NSData backData = [backStr dataUsingEncoding:NSUTF8StringEncoding];    [sock writeData:backData withTimeout:-1 tag:ECHO_MSG];}

- (void)onSocket:(AsyncSocket )sock willDisconnectWithError:(NSError )err{    [self logInfo:FORMAT(@”Client Disconnected: %@:%hu“, [sock connectedHost], [sock connectedPort])];}

- (void)onSocketDidDisconnect:(AsyncSocket *)sock{    [connectedSockets removeObject:sock];}

@end