即时通讯：第一阶段（登录和注册）

首先是配置XMPP环境，然后建立一个工程，需要建立Core Data的项目，要引入三个框架，如下图，因为用到的XMPPFramework第三方框架中用到了XML解析，所以还要在设置中设置Header Search Paths为/usr/include/libxml2，Other Linker Flags改为-lxml2

XMPPManger.h

#import <Foundation/Foundation.h>
#import "XMPPFramework.h"  // 引入

@interface XMPPManger : NSObject

/**
 *  声明一个通道的属性
 */
@property (nonatomic, strong) XMPPStream *xmppStream;

// 创建单例
+ (instancetype)shareMangaged;

// 登录的方法
- (void)loginWithUserName:(NSString *)userName password:(NSString *)password;

// 注册的方法
- (void)registerWithUserName:(NSString *)userName password:(NSString *)password;

@end

XMPPManger.m

#import "XMPPManger.h"

// 列举枚举（登录和注册）
typedef NS_ENUM(NSUInteger, ConnectToServerPurpose) {
    ConnectToServerPurposeLogin,
    ConnectToServerPurposeRegister,
};


@interface XMPPManger () <XMPPStreamDelegate>

// 登录的属性
@property (nonatomic, strong) NSString *userName;  // 用户名
@property (nonatomic, strong) NSString *password;  // 密码

// 注册的属性
@property (nonatomic, strong) NSString *registerUserName;  // 用户名
@property (nonatomic, strong) NSString *registerPassword;  // 密码

// 记录当前是登录还是注册
@property (nonatomic) ConnectToServerPurpose connectToserver;

@end


static XMPPManger *xmpp = nil;

@implementation XMPPManger

// 实现创建单例
+ (instancetype)shareMangaged {
    
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        xmpp = [[XMPPManger alloc] init];
    });
    return xmpp;
}


#pragma mark - 创建通道
- (instancetype)init {
    
    if (self = [super init]) {
        
        // 初始化通道对象
        self.xmppStream = [[XMPPStream alloc] init];
        
        // 设置openfire服务器地址
        self.xmppStream.hostName = kHostName;
        
        // 设置服务器端口号
        self.xmppStream.hostPort = kHostPort;
        
        // 添加代理
        [self.xmppStream addDelegate:self delegateQueue:dispatch_get_main_queue()];
    }
    return self;
}


#pragma mark - 登录和注册的方法
// 登录的方法实现
- (void)loginWithUserName:(NSString *)userName password:(NSString *)password {
    
    self.userName = userName;
    self.password = password;
    
    // 记录登录状态
    self.connectToserver = ConnectToServerPurposeLogin;
    
    // 链接服务器
    [self linkServer];
}

// 注册的方法实现
- (void)registerWithUserName:(NSString *)userName password:(NSString *)password {
    
    self.registerUserName = userName;
    self.registerPassword = password;
    
    // 记录登录状态
    self.connectToserver = ConnectToServerPurposeRegister;
    
    // 链接服务器
    [self linkServer];
}


#pragma mark - 链接服务器
- (void)linkServer {
    
    NSString *string = [[NSString alloc] init];
    // 区分具体是登录还是注册
    switch (self.connectToserver) {
        case ConnectToServerPurposeLogin:
            string = [NSString stringWithFormat:@"%@", self.userName];
            break;
        case ConnectToServerPurposeRegister:
            string = [NSString stringWithFormat:@"%@", self.registerUserName];
            break;
            
        default:
            break;
    }
    
    // 要链接服务器，要有用户什么认证
    // 身份证
    // 参数1：用户名
    // 参数2：域名
    // 参数3：资源
    XMPPJID *jid = [XMPPJID jidWithUser:string domain:kDomin resource:kResource];
    
    // 通过通道进行身份验证
    self.xmppStream.myJID = jid;
    
    
    // 如果当前聊天工具处于链接状态或者已经链接了，此时，你需要去切断链接，【此逻辑不唯一】
    if ([self.xmppStream isConnected] || [self.xmppStream isConnecting]) {
        [self disconnectToServer];
    }
    
    // 链接超时
    NSError *error = nil;
    [self.xmppStream connectWithTimeout:5 error:&error];
    
    if (error) {
        NSLog(@"服务器链接超时");
    }
}


// 断开链接
- (void)disconnectToServer {
    
    // 当前用户下线了
    XMPPPresence *presence = [XMPPPresence presenceWithType:@"unavailable"];
    
    // 告诉通道下线了
    [self.xmppStream sendElement:presence];
    
    // 使通道失去链接
    [self.xmppStream disconnect];
}


#pragma mark - XMPPStreamDelegate协议方法
#pragma mark - 链接超时
- (void)xmppStreamConnectDidTimeout:(XMPPStream *)sender {
    
    NSLog(@"链接超时");
}


#pragma mark - 链接成功
- (void)xmppStreamDidConnect:(XMPPStream *)sender {
    
    NSLog(@"链接成功");
    
        // 区分登录和注册进行密码验证
    switch (self.connectToserver) {
        case ConnectToServerPurposeLogin:
            // 登录密码的验证
            [self.xmppStream authenticateWithPassword:self.password error:nil];
            break;
            
        case ConnectToServerPurposeRegister:
            // 注册密码的验证
            [self.xmppStream registerWithPassword:self.registerPassword error:nil];
            break;
        default:
            break;
    }
}


#pragma mark - 断开链接
- (void)xmppStreamDidDisconnect:(XMPPStream *)sender withError:(NSError *)error {
    
    // 1.自己手动断开
    
    // 2.被动断开
    
    if (error) {
        NSLog(@"断开链接，error = %@", error);
    }
}


#pragma mark - 认证失败(登录失败)
- (void)xmppStream:(XMPPStream *)sender didNotAuthenticate:(DDXMLElement *)error {
    
    NSLog(@"认证失败, error = %@", error);
}


#pragma mark - 认证成功(登录成功)
- (void)xmppStreamDidAuthenticate:(XMPPStream *)sender {
    
    // 上线
    XMPPPresence *presennce = [XMPPPresence presenceWithType:@"available"];
    [self.xmppStream sendElement:presennce];
    
    NSLog(@"登录成功");
}

@end

LoginViewcontroller.m（登录）

#import "LoginViewcontroller.h"
#import "XMPPManger.h"

@interface LoginViewcontroller ()

@property (weak, nonatomic) IBOutlet UITextField *nameLabel;
@property (weak, nonatomic) IBOutlet UITextField *passwordLabel;

@end

@implementation LoginViewcontroller

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}


// 登录按钮点击事件
- (IBAction)loginAction:(UIButton *)sender {
    
    [[XMPPManger shareMangaged] loginWithUserName:self.nameLabel.text password:self.passwordLabel.text];
}

@end

RegisterViewController.m（注册）

因为我们使用的是模态推出，所以我们点击注册按钮的同时需要返回到上一页，因此，注册所用的一些方法我们可以放在此文件中写，都在XMPPManger.m中也可以

#import "RegisterViewController.h"
#import "XMPPManger.h"

@interface RegisterViewController () <XMPPStreamDelegate>

@property (weak, nonatomic) IBOutlet UITextField *nameTextField;
@property (weak, nonatomic) IBOutlet UITextField *passwordTextfield;

@end

@implementation RegisterViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    [[XMPPManger shareMangaged].xmppStream addDelegate:self delegateQueue:dispatch_get_main_queue()];
}


// 注册的方法
- (IBAction)registerAction:(UIButton *)sender {
    
    [[XMPPManger shareMangaged] registerWithUserName:self.nameTextField.text password:self.passwordTextfield.text];
}


#pragma mark - XMPPStreamDelegate实现协议方法
// 实现协议是为了实现需求：注册成功之后dismiss到登录界面
// 注册成功
- (void)xmppStreamDidRegister:(XMPPStream *)sender {
    
    NSLog(@"注册成功");
    
    [self dismissViewControllerAnimated:YES completion:^{
        
    }];
}


// 注册失败
- (void)xmppStream:(XMPPStream *)sender didNotRegister:(DDXMLElement *)error {
    
    NSLog(@"注册失败 = %@", error);
}

@end