iOS項目開發之Socket編程

有一段時間沒有認真總結和寫博客了

前段時間找工做、進入工做階段。比較少靜下來認真總結，如今靜下心來總結一下最近的一些心得

• 前言
• AsyncSocket介紹
• AsyncSocket詳解
• AsyncSocket示例

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1、前言

公司的項目用到了Socket編程，以前在學習的過程中，用到的更多的仍是http請求的方式。可是既然用到了就必須學習一下，因此就在網上找一些例子，而後想本身寫一個demo。但是發現不少寫iOS Socket的博客並無很詳細的說明，也多是大神們以爲其餘東西都淺顯易懂。

本身專研了一下，將本身的一些理解總結出來，一方面整理本身的學習思路，另外一方面，爲一些和我有一樣困惑的小夥伴們，稍作指引。

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 2、AsyncSocket介紹

1⃣️iOS中Socket編程的方式有哪些？

－BSD Socket

BSD Socket 是UNIX系統中通用的網絡接口，它不只支持各類不一樣的網絡類型，並且也是一種內部進程之間的通訊機制。而iOS系統其實本質就是UNIX，因此能夠用，可是比較複雜。

－CFSocket

CFSocket是蘋果提供給咱們的使用Socket的方式，可是用起來仍是會不太順手。固然想使用的話，能夠細細研究一下。

－AsyncSocket

此次博客的主講內容，也是咱們在開發項目中常常會用到的。

2⃣️爲何選擇AsyncSocket？

iphone的CFNetwork編程比較艱深。使用AsyncSocket開源庫來開發相對較簡單，幫助咱們封裝了不少東西。

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3、AsyncSocket詳解

 1⃣️說明

在咱們開發當中，咱們主要的任務是開發客戶端。因此詳解裏主要將客戶端的整個鏈接創建過程，以及在說明時候回調哪些函數。在後面的示例代碼中，也會給出服務器端的簡單開發。

2⃣️過程詳解

1.創建鏈接

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

2.鏈接成功後，會回調的函數

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

3.發送數據

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

4.接受數據

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

5.斷開鏈接

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

- (void)onSocketDidDisconnect:(AsyncSocket *)sock

主要就是上述的幾個方法，只是說在真正開發當中，極可能咱們在收發數據的時候，咱們收發的數據並不只僅是一個字符串包裝成NSData便可，咱們極可能會發送結構體等類型，這個時候咱們就須要和服務器端的人員協做來開發：定義怎樣的結構體。

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4、AsyncSocket示例

客戶端代碼

#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)
    {
        // 在須要聯接地方使用connectToHost聯接服務器
        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
// 發送數據
- (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];
}
// 鏈接/從新鏈接
- (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
{
}

// 接收到數據（能夠經過tag區分）
-(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

服務器端代碼

#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; // 會隨即取端口
        }
        
        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];
}

// 客戶鏈接成功！
- (void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port
{
    [self logInfo:FORMAT(@"Accepted client %@:%hu", host, port)];
    
    NSString *welcomeMsg = @"恭喜您,已經經過scoket鏈接上服務器!";
    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];
}
// 接收到數據
- (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:@"我說: %@",recvMsg];
        } else {
            backStr = [NSString stringWithFormat:@"他說: %@",recvMsg];
        }
    }
    
    // 回發數據
    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

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