Question

几天之内，我尝试实现一个应用程序，该程序可在我的网络中浏览Bonjour-Services并将其显示在控制台中（第一步）。我用NSNetServiceBrowser实现了一个类，并按照此处许多文章中的说明对其进行了初始化。但是找到服务后，我无法解析它以使主机名可供我使用。服务解析始终会导致错误

-72004（NSNetServicesBadArgumentError）。

我尝试使用 @“ local。” 作为域或我的特定服务来查找，而不是使用 @“ _ services._dns-sd。 _udp。” ，但这都导致相同的结果。

//
//  Bonjour.m
//  BonjourTest 
//
//  Created by PellePe on 21.07.18.
//  Copyright © 2018 PellePe. All rights reserved.
//

#import "Bonjour.h"
#import <Foundation/Foundation.h>

#include <netinet/in.h>


#define SERVICE_DOMAIN @"local"
#define SERVICE_TYPE   @"_bonjourTest._tcp"
#define SERVICE_NAME   @"Bonjour Test"

@interface Bonjour () <NSNetServiceDelegate, NSNetServiceBrowserDelegate>

@property (nonatomic, strong) NSMutableArray<NSNetService *> *detectedServices;
@property (nonatomic, strong) NSNetServiceBrowser *netServiceBrowser;

@end


@implementation Bonjour

#pragma mark -
#pragma mark Service Browsing

- (BOOL)isBrowsing {
    return self.netServiceBrowser != NULL;
}

- (void)startServiceBrowsing:(NSString *)type {
    if (self.detectedServices == NULL) {
        self.detectedServices = [[NSMutableArray<NSNetService*> alloc] init];
    } else {
        [self.detectedServices removeAllObjects];
    }

    self.netServiceBrowser = [[NSNetServiceBrowser alloc] init];
    self.netServiceBrowser.includesPeerToPeer = YES;
    self.netServiceBrowser.delegate = self;

    [self.netServiceBrowser searchForServicesOfType: type  // SERVICE_TYPE
                                       inDomain: @""];
}

- (void)stopServiceBrowsing {
    assert(self.netServiceBrowser != NULL);

    [self.netServiceBrowser stop];
    self.netServiceBrowser = NULL;
}

#pragma mark -
#pragma NSNetServiceDelegate

-(void)netServiceWillResolve:(NSNetService *)sender {
    NSLog(@"netService will resolve - %@", sender.hostName);
}

- (void)netService:(NSNetService *)sender
     didNotResolve:(NSDictionary<NSString *,NSNumber *> *)errorDict {
    NSLog(@"netService did not resolve");

    for (NSString *key in [errorDict allKeys]) {
        NSLog(@"%@: %@", key, [errorDict objectForKey: key]);
    }
}

- (void)netServiceDidResolveAddress:(NSNetService *)sender {
    NSLog(@"netService did resolve address - %@", sender.hostName);  
}

#pragma mark -
#pragma mark NSNetServiceBrowserDelegate

- (void)netServiceBrowserWillSearch:(NSNetServiceBrowser *)browser {
    NSLog(@"Browser will search");
}

- (void)netServiceBrowserDidStopSearch:(NSNetServiceBrowser *)browser {
    NSLog(@"Browser did stop search");
}

- (void)netServiceBrowser:(NSNetServiceBrowser *)browser     didFindService:(NSNetService *)service moreComing:(BOOL)moreComing {
    [self.detectedServices addObject: service];

    service.delegate = self;
    [service resolveWithTimeout: 100];

    NSLog(@"Find service: %@ - %@ - %@ (%@)", service.name, service.hostName, service.type, moreComing ? @"YES" : @"No");
}

- (void)netServiceBrowser:(NSNetServiceBrowser *)browser didRemoveService:(NSNetService *)service moreComing:(BOOL)moreComing {
    NSLog(@"Remove service: %@ - %@ - %@", service.name, service.hostName, service.type);
}

@end

我在网上搜索了多个小时，但找不到关于错误-72004 的任何提示。使用NSNetServiceBrowser对服务的初始化方式没有影响。

有人知道它出了什么问题吗？

Answer 1

所以这里的问题是，当您搜索_services._dns-sd._udp.时，您将不会获得实际的服务，但是您会获得所有的服务类型，例如。

let browser = NetServiceBrowser()
browser.searchForServices(ofType: "_googlecast._tcp", inDomain: "local")

此查询将返回如下所示的服务

NetService(domain: "local", type: "_googlecast._tcp", name: "RoomTV")

这是有效的，您可以毫无问题地解决，但是当您这样浏览时：

browser.searchForServices(ofType: "_services._dns-sd._udp.", inDomain: "local")

返回的服务如下所示：

NetService(domain: ".", type: "_tcp.local.", name: "_googlecast")

因此，要解决此问题，您需要使用新类型再次进行搜索以获取实际的服务。

let type = "\(service.name).\(service.type)"
               .replacingOccurrences(of: "local.", with: "")
browser.searchForServices(ofType: type, inDomain: "local")

NSNetServiceBrowsing无法解析错误为-72004的服务

1 个答案: