SocketRocket

websocket 实现了 客户端和服务器 一次握手 就可以不断接受服务器消息的功能

具体原理可以看这里WebSocket 是什么原理？
websocket是http协议上的升级 好像ws前缀是http,wss前缀的就是https了。
facebook出了一个websocket的开源库 挺好用。下面是使用方法:

pod

pod 'SocketRocket', '~> 0.4.2'

import

#import "SRWebSocket.h"

初始化

- (void)Reconnect{
    self.webSocket.delegate = nil;
    [self.webSocket close];

    self.webSocket = [[SRWebSocket alloc] initWithURLRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"ws://echo.websocket.org"]]];
    self.webSocket.delegate = self;

    self.title = @"Opening Connection...";

    [self.webSocket open];
}

- (void)viewWillAppear:(BOOL)animated{
    [self Reconnect];
}

- (void)viewDidDisappear:(BOOL)animated{
    // Close WebSocket
    self.webSocket.delegate = nil;
    [self.webSocket close];
    self.webSocket = nil;
}

实现代理方法

#pragma mark - SRWebSocketDelegate
- (void)webSocketDidOpen:(SRWebSocket *)webSocket{
    NSLog(@"Websocket Connected");
    self.title = @"Connected!";
}

- (void)webSocket:(SRWebSocket *)webSocket didFailWithError:(NSError *)error{
    NSLog(@":( Websocket Failed With Error %@", error);

    self.title = @"Connection Failed! (see logs)";
    self.webSocket = nil;
}

- (void)webSocket:(SRWebSocket *)webSocket didReceiveMessage:(id)message{
    xxx
}

这样就能不停的重服务器获取信息，而且只需要发送一次请求。
很适合消息通知类的功能。