NSNetService出版，但didAcceptConnectionWithInputStream..。从来没有叫过

Question

我一直试图在iOS上制作一个简单的应用程序，它将接收一条消息，然后根据该消息执行一个操作(目前我只想通过NSLog展示它)。我可以连接到服务，但服务似乎从来没有收到任何东西。这是我的.h文件：

#import <Foundation/Foundation.h>
#import <arpa/inet.h>

@interface PalServiceController : NSObject <NSNetServiceDelegate>

@property (nonatomic, strong) NSNetService *ns;
@property (nonatomic, strong) NSOutputStream *ostream;

- (void)start;
+ (int)getPort;
- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)eventCode;

@end

我的.m：

#import "PalServiceController.h"

@implementation PalServiceController

- (void)start
{
    // Start a net service
    int port = [PalServiceController getPort];
    NSLog(@"Opening on port %i", port);
    self.ns = [[NSNetService alloc] initWithDomain:@""
                                              type:@"_TestingProtocol._tcp."
                                              name:@"Test Name For iPhone"
                                              port:port];
    if (self.ns) {
        [self.ns setDelegate:self];
        [self.ns publish];
        self.ns.delegate = self;
    } else {
        NSLog(@"Error starting service");
    }

}

/*
 * Code from: http://stackoverflow.com/a/11723158/657676
 */
+ (int) getPort
{
 ...   
}

- (void)netServiceWillResolve:(NSNetService *)sender
{
    NSLog(@"Resolving");
}

- (void)netServiceDidResolveAddress:(NSNetService *)sender
{
    NSLog(@"Resolved Address");
}

- (void)netService:(NSNetService *)sender didNotPublish:(NSDictionary *)errorDict
{
    NSLog(@"Error publishing");
}

- (void)netService:(NSNetService *)sender didAcceptConnectionWithInputStream:(NSInputStream *)inputStream outputStream:(NSOutputStream *)outputStream
{
    NSLog(@"Got a connection! (server)");
    // Close self down
    [self.ns stopMonitoring];
    [self.ns stop];
}

- (void)netService:(NSNetService *)sender didNotResolve:(NSDictionary *)errorDict
{
    NSLog(@"Error resolving");
}
- (void)netServiceDidPublish:(NSNetService *)sender
{
    NSLog(@"Published server");
}

- (void)netServiceDidStop:(NSNetService *)sender
{
    NSLog(@"Server stopped");
}

- (void)netService:(NSNetService *)sender didUpdateTXTRecordData:(NSData *)data
{
    NSLog(@"Updated TXT Record");
}

- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)eventCode
{
    NSLog(@"Event on server");
    switch(eventCode) {
        ...
    }
}

@end

这被称为via：

self.controller = [[PalServiceController alloc] init];
[self.controller start];

当我使用Bonjour浏览器时，我可以看到服务，当我使用自己的NSNetServiceBrowser实现或Bill (博客帖子，代码)的示例时，它似乎是连接的(也就是说，我自己的实现通过stream:(NSStream *)stream handleEvent:(NSStreamEvent)eventCode接收NSStreamEventHasSpaceAvailable和NSStreamEventOpenCompleted事件)。但是，服务器上没有调用上述任何方法。

我仍然是iOS的新手，所以我希望这只是一个愚蠢的错误，可以很容易地修复。

Answer 1

-[NSNetService publish]只是发布服务；您负责创建一个套接字并侦听给NSNetService初始化程序的端口。您不会收到netService:didAcceptConnectionWithInputStream:outputStream:，因为NSNetService对套接字一无所知。

如果您希望NSNetService为您管理套接字并发送didAcceptConnection...-use -[NSNetService publishWithOptions:]

[self.ns publishWithOptions:NSNetServiceListenForConnections];

在这种情况下，您需要确保初始化NSNetService的端口是未使用的。您的getPort方法从不关闭套接字(并且泄漏CFSocketRef)，因此在发布服务时将使用它，从而导致错误。

我建议您删除getPort，并如苹果在NSNetServices.h中所建议的那样，“指定端口号为零以使用随机端口”。