0.准备

pod 'SocketRocket'
#import "SRWebSocket.h"
@interface LongConnect ()<SRWebSocketDelegate>

1.创建

    NSString *urlStr = [NSString stringWithFormat:@"ws://192.168.1.112:8080/dev/echo/?username=%@&companyname=%@", [df objectForKey:@"username"], [df objectForKey:@"companyname"]];
    self.webSocket = [[SRWebSocket alloc] initWithURLRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:urlStr]]];
// 遵守SRWebSocketDelegate协议
    self.webSocket.delegate = self;
// 打开
    [self.webSocket open];

2.关闭

// 销毁长链接

    // 关闭之后不可以再open，必须重新创建一个新的连接对象
    [self.webSocket close];

2. SRWebSocketDelegate协议实现

// 1. 已经打开连接
- (void)webSocketDidOpen:(SRWebSocket *)webSocket;
// 2. 失败
- (void)webSocket:(SRWebSocket *)webSocket didFailWithError:(NSError *)error;
//3. 接收数据
- (void)webSocket:(SRWebSocket *)webSocket didReceiveMessage:(id)message{
    NSLog(@"%@", message);

    // 如果接收的是Jons字符串，可以转字典。如果是一对多接收，可以使用广播
    NSDictionary *dic = [NSString parseJSONStringToNSDictionary:message];
    [self.notificationCenter postNotificationName:@"长链接数据" object:nil userInfo:dic];
    
}