iOS即時通信之簡單聊天室

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#import "ViewController.h"

@interface ViewController ()<NSStreamDelegate,UITextFieldDelegate,UITableViewDataSource,UITableViewDelegate>{
    NSInputStream *_inputStream;//對應輸入流
    NSOutputStream *_outputStream;//對應輸出流
}
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *inputViewConstraint;
@property (weak, nonatomic) IBOutlet UITableView *tableView;

@property (nonatomic, strong) NSMutableArray *chatMsgs;//聊天消息數組

@end

@implementation ViewController

-(NSMutableArray *)chatMsgs{
    if (!_chatMsgs) {
        _chatMsgs = [NSMutableArray array];
    }
    
    return _chatMsgs;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
  
    
    // 2.收發數據
    // 作一個聊天
    // 1.用戶登陸
    // 2.收發數據
    
    // 監聽鍵盤
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(kbFrmWillChange:) name:UIKeyboardWillChangeFrameNotification object:nil];
}


-(void)kbFrmWillChange:(NSNotification *)noti{
    NSLog(@"%@",noti.userInfo);
    
    // 獲取窗口的高度
    
    CGFloat windowH = [UIScreen mainScreen].bounds.size.height;
    
   
    
    // 鍵盤結束的Frm
    CGRect kbEndFrm = [noti.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
     // 獲取鍵盤結束的y值
    CGFloat kbEndY = kbEndFrm.origin.y;
    
    
    self.inputViewConstraint.constant = windowH - kbEndY;
}

-(void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode{
    NSLog(@"%@",[NSThread currentThread]);

//    NSStreamEventOpenCompleted = 1UL << 0,//輸入輸出流打開完成
//    NSStreamEventHasBytesAvailable = 1UL << 1,//有字節可讀
//    NSStreamEventHasSpaceAvailable = 1UL << 2,//能夠發放字節
//    NSStreamEventErrorOccurred = 1UL << 3,// 鏈接出現錯誤
//    NSStreamEventEndEncountered = 1UL << 4// 鏈接結束
    switch (eventCode) {
        case NSStreamEventOpenCompleted:
            NSLog(@"輸入輸出流打開完成");
            break;
        case NSStreamEventHasBytesAvailable:
            NSLog(@"有字節可讀");
            [self readData];
            break;
        case NSStreamEventHasSpaceAvailable:
            NSLog(@"能夠發送字節");
            break;
        case NSStreamEventErrorOccurred:
                        NSLog(@" 鏈接出現錯誤");
            break;
        case NSStreamEventEndEncountered:
             NSLog(@"鏈接結束");
            
            // 關閉輸入輸出流
            [_inputStream close];
            [_outputStream close];
            
            // 從主運行循環移除
            [_inputStream removeFromRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
            [_outputStream removeFromRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
            break;
        default:
            break;
    }
    
}

- (IBAction)connectToHost:(id)sender {
    // 1.創建鏈接
    NSString *host = @"127.0.0.1";
    int port = 12345;
    
    // 定義C語言輸入輸出流
    CFReadStreamRef readStream;
    CFWriteStreamRef writeStream;
    CFStreamCreatePairWithSocketToHost(NULL, (__bridge CFStringRef)host, port, &readStream, &writeStream);
    
    // 把C語言的輸入輸出流轉化成OC對象
    _inputStream = (__bridge NSInputStream *)(readStream);
    _outputStream = (__bridge NSOutputStream *)(writeStream);
    
    
    // 設置代理
    _inputStream.delegate = self;
    _outputStream.delegate = self;
    
    
    // 把輸入輸出流添加到主運行循環
    // 不添加主運行循環 代理有可能不工做
    [_inputStream scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
    [_outputStream scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
    
    // 打開輸入輸出流
    [_inputStream open];
    [_outputStream open];
}


- (IBAction)loginBtnClick:(id)sender {
    
    // 登陸
    // 發送用戶名和密碼
    // 在這裏作的時候，只發用戶名，密碼就不用發送
    
    // 若是要登陸，發送的數據格式爲 "iam:zhangsan";
    // 若是要發送聊天消息，數據格式爲 "msg:did you have dinner";
    
    //登陸的指令
    NSString *loginStr = @"iam:zhangsan";
    
    //把Str轉成NSData
    NSData *data = [loginStr dataUsingEncoding:NSUTF8StringEncoding];

    
    [_outputStream write:data.bytes maxLength:data.length];
}

#pragma mark 讀取服務器返回的數據
-(void)readData{
    
    //創建一個緩衝區 能夠放1024個字節
    uint8_t buf[1024];
    
    // 返回實際裝的字節數
    NSInteger len = [_inputStream read:buf maxLength:sizeof(buf)];

    // 把字節數組轉化成字符串
    NSData *data = [NSData dataWithBytes:buf length:len];
    
    // 從服務器接收到的數據
    NSString *recStr =  [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    
    NSLog(@"%@",recStr);
    
    [self reloadDataWithText:recStr];
    
}

-(BOOL)textFieldShouldReturn:(UITextField *)textField{
    
    NSString *text = textField.text;
    
    NSLog(@"%@",text);
    // 聊天信息
    NSString *msgStr = [NSString stringWithFormat:@"msg:%@",text];
    
    //把Str轉成NSData
    NSData *data = [msgStr dataUsingEncoding:NSUTF8StringEncoding];
    
    // 刷新表格
    [self reloadDataWithText:msgStr];
    
    // 發送數據
    [_outputStream write:data.bytes maxLength:data.length];
    
    // 發送完數據，清空textField
    textField.text = nil;
    
    return YES;
}

-(void)reloadDataWithText:(NSString *)text{
    [self.chatMsgs addObject:text];
    
    [self.tableView reloadData];
    
    // 數據多，應該往上滾動
    NSIndexPath *lastPath = [NSIndexPath indexPathForRow:self.chatMsgs.count - 1 inSection:0];
    [self.tableView scrollToRowAtIndexPath:lastPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}

#pragma mark 表格的數據源

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return self.chatMsgs.count;
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *ID = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
   
    cell.textLabel.text = self.chatMsgs[indexPath.row];
    
    return cell;
}

-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
    [self.view endEditing:YES];
}
@end

 ps:注意：

1.前提須要鏈接服務器

2.輸入輸出流須要添加到主運行循環

3.輸入流：用來寫數據

4.輸出流：用來讀數據

步驟總結：

1.創建鏈接，設置ip和端口號

2.經過創建C語言輸入輸出流，鏈接服務器，再把C語言的輸入輸出流轉換成OC對象

3.設置OC類型的輸入輸出流代理爲當前控制器

4.把輸入輸出流添加到主運行循環當中，打開輸入輸出流

5.客戶端向服務器發送數據（輸出流）

6.服務器向客戶端返回數據（輸入流）

7.當前控制器刷新主界面數據

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