因此，我在主线程中拥有所有与多点连接相关的代码。我有一个 MCSession、MCNearbyServiceAdvertiser 和一个 MCNearbyServiceBrowser。这些都是用 peerID 创建的，我确保只有一个发送邀请。

session 已连接。我的问题是，两个客户端需要大约 20-30 秒才能连接。这是 Not Acceptable 。客户使用良好的 Wifi 和蓝牙。我希望浏览、邀请处理程序和连接发生在 1 秒内。有谁知道是什么在减慢速度？

代码完全按照这里提供的，我还实现了certificateHandler(YES)

@interface SessionController () // Class extension
@property (nonatomic, strong) MCPeerID *peerID;
@property (nonatomic, strong) MCSession *session;
@property (nonatomic, strong) MCNearbyServiceAdvertiser *serviceAdvertiser;
@property (nonatomic, strong) MCNearbyServiceBrowser *serviceBrowser;

// Connected peers are stored in the MCSession
// Manually track connecting and disconnected peers
@property (nonatomic, strong) NSMutableOrderedSet *connectingPeersOrderedSet;
@property (nonatomic, strong) NSMutableOrderedSet *disconnectedPeersOrderedSet;
@end

@implementation SessionController

static NSString * const kMCSessionServiceType = @"mcsessionp2p";

#pragma mark - Initializer

- (instancetype)init
{
    self = [super init];

    if (self)
    {
        _peerID = [[MCPeerID alloc] initWithDisplayName:[[UIDevice currentDevice] name]];

        _connectingPeersOrderedSet = [[NSMutableOrderedSet alloc] init];
        _disconnectedPeersOrderedSet = [[NSMutableOrderedSet alloc] init];

        NSNotificationCenter *defaultCenter = [NSNotificationCenter defaultCenter];

        // Register for notifications
        [defaultCenter addObserver:self
                          selector:@selector(startServices)
                              name:UIApplicationWillEnterForegroundNotification
                            object:nil];

        [defaultCenter addObserver:self
                          selector:@selector(stopServices)
                              name:UIApplicationDidEnterBackgroundNotification
                            object:nil];

        [self startServices];

        _displayName = self.session.myPeerID.displayName;
    }

    return self;
}

#pragma mark - Memory management

- (void)dealloc
{
    // Unregister for notifications on deallocation.
    [[NSNotificationCenter defaultCenter] removeObserver:self];

    // Nil out delegates
    _session.delegate = nil;
    _serviceAdvertiser.delegate = nil;
    _serviceBrowser.delegate = nil;
}

#pragma mark - Override property accessors

- (NSArray *)connectedPeers
{
    return self.session.connectedPeers;
}

- (NSArray *)connectingPeers
{
    return [self.connectingPeersOrderedSet array];
}

- (NSArray *)disconnectedPeers
{
    return [self.disconnectedPeersOrderedSet array];
}

#pragma mark - Private methods

- (void)setupSession
{
    // Create the session that peers will be invited/join into.
    _session = [[MCSession alloc] initWithPeer:self.peerID];
    self.session.delegate = self;

    // Create the service advertiser
    _serviceAdvertiser = [[MCNearbyServiceAdvertiser alloc] initWithPeer:self.peerID
                                                           discoveryInfo:nil
                                                             serviceType:kMCSessionServiceType];
    self.serviceAdvertiser.delegate = self;

    // Create the service browser
    _serviceBrowser = [[MCNearbyServiceBrowser alloc] initWithPeer:self.peerID
                                                       serviceType:kMCSessionServiceType];
    self.serviceBrowser.delegate = self;
}

- (void)teardownSession
{
    [self.session disconnect];
    [self.connectingPeersOrderedSet removeAllObjects];
    [self.disconnectedPeersOrderedSet removeAllObjects];
}

- (void)startServices
{
    [self setupSession];
    [self.serviceAdvertiser startAdvertisingPeer];
    [self.serviceBrowser startBrowsingForPeers];
}

- (void)stopServices
{
    [self.serviceBrowser stopBrowsingForPeers];
    [self.serviceAdvertiser stopAdvertisingPeer];
    [self teardownSession];
}

- (void)updateDelegate
{    
    [self.delegate sessionDidChangeState];
}

- (NSString *)stringForPeerConnectionState:(MCSessionState)state
{
    switch (state) {
        case MCSessionStateConnected:
            return @"Connected";

        case MCSessionStateConnecting:
            return @"Connecting";

        case MCSessionStateNotConnected:
            return @"Not Connected";
    }
}

#pragma mark - MCSessionDelegate protocol conformance

- (void)session:(MCSession *)session peer:(MCPeerID *)peerID didChangeState:(MCSessionState)state
{
    NSLog(@"Peer [%@] changed state to %@", peerID.displayName, [self stringForPeerConnectionState:state]);

    switch (state)
    {
        case MCSessionStateConnecting:
        {
            [self.connectingPeersOrderedSet addObject:peerID];
            [self.disconnectedPeersOrderedSet removeObject:peerID];
            break;
        }

        case MCSessionStateConnected:
        {
            [self.connectingPeersOrderedSet removeObject:peerID];
            [self.disconnectedPeersOrderedSet removeObject:peerID];
            break;
        }

        case MCSessionStateNotConnected:
        {
            [self.connectingPeersOrderedSet removeObject:peerID];
            [self.disconnectedPeersOrderedSet addObject:peerID];
            break;
        }
    }

    [self updateDelegate];
}

- (void)session:(MCSession *)session didReceiveData:(NSData *)data fromPeer:(MCPeerID *)peerID
{
    // Decode the incoming data to a UTF8 encoded string
    NSString *receivedMessage = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

    NSLog(@"didReceiveData %@ from %@", receivedMessage, peerID.displayName);
}

- (void)session:(MCSession *)session didStartReceivingResourceWithName:(NSString *)resourceName fromPeer:(MCPeerID *)peerID withProgress:(NSProgress *)progress
{
    NSLog(@"didStartReceivingResourceWithName [%@] from %@ with progress [%@]", resourceName, peerID.displayName, progress);
}

- (void)session:(MCSession *)session didFinishReceivingResourceWithName:(NSString *)resourceName fromPeer:(MCPeerID *)peerID atURL:(NSURL *)localURL withError:(NSError *)error
{
    NSLog(@"didFinishReceivingResourceWithName [%@] from %@", resourceName, peerID.displayName);

    // If error is not nil something went wrong
    if (error)
    {
        NSLog(@"Error [%@] receiving resource from %@ ", [error localizedDescription], peerID.displayName);
    }
    else
    {
        // No error so this is a completed transfer.  The resources is located in a temporary location and should be copied to a permenant location immediately.
        // Write to documents directory
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *copyPath = [NSString stringWithFormat:@"%@/%@", [paths firstObject], resourceName];
        if (![[NSFileManager defaultManager] copyItemAtPath:[localURL path] toPath:copyPath error:nil])
        {
            NSLog(@"Error copying resource to documents directory");
        }
        else
        {
            // Get a URL for the path we just copied the resource to
            NSURL *url = [NSURL fileURLWithPath:copyPath];
            NSLog(@"url = %@", url);
        }
    }
}

// Streaming API not utilized in this sample code
- (void)session:(MCSession *)session didReceiveStream:(NSInputStream *)stream withName:(NSString *)streamName fromPeer:(MCPeerID *)peerID
{
    NSLog(@"didReceiveStream %@ from %@", streamName, peerID.displayName);
}

#pragma mark - MCNearbyServiceBrowserDelegate protocol conformance

// Found a nearby advertising peer
- (void)browser:(MCNearbyServiceBrowser *)browser foundPeer:(MCPeerID *)peerID withDiscoveryInfo:(NSDictionary *)info
{
    NSString *remotePeerName = peerID.displayName;

    NSLog(@"Browser found %@", remotePeerName);

    MCPeerID *myPeerID = self.session.myPeerID;

    BOOL shouldInvite = ([myPeerID.displayName compare:remotePeerName] == NSOrderedDescending);

    if (shouldInvite)
    {
        NSLog(@"Inviting %@", remotePeerName);
        [browser invitePeer:peerID toSession:self.session withContext:nil timeout:30.0];
    }
    else
    {
        NSLog(@"Not inviting %@", remotePeerName);
    }

    [self updateDelegate];
}

- (void)browser:(MCNearbyServiceBrowser *)browser lostPeer:(MCPeerID *)peerID
{
    NSLog(@"lostPeer %@", peerID.displayName);

    [self.connectingPeersOrderedSet removeObject:peerID];
    [self.disconnectedPeersOrderedSet addObject:peerID];

    [self updateDelegate];
}

- (void)browser:(MCNearbyServiceBrowser *)browser didNotStartBrowsingForPeers:(NSError *)error
{
    NSLog(@"didNotStartBrowsingForPeers: %@", error);
}

#pragma mark - MCNearbyServiceAdvertiserDelegate protocol conformance

- (void)advertiser:(MCNearbyServiceAdvertiser *)advertiser didReceiveInvitationFromPeer:(MCPeerID *)peerID withContext:(NSData *)context invitationHandler:(void(^)(BOOL accept, MCSession *session))invitationHandler
{
    NSLog(@"didReceiveInvitationFromPeer %@", peerID.displayName);

    invitationHandler(YES, self.session);

    [self.connectingPeersOrderedSet addObject:peerID];
    [self.disconnectedPeersOrderedSet removeObject:peerID];

    [self updateDelegate];
}

- (void)advertiser:(MCNearbyServiceAdvertiser *)advertiser didNotStartAdvertisingPeer:(NSError *)error
{
    NSLog(@"didNotStartAdvertisingForPeers: %@", error);
}

@end

最佳答案

我已经注意到这个问题，但我似乎无法弄清楚这里发生了什么，在调试时似乎在触发状态更改通知之间存在巨大的延迟，这可能与 View 本身有关.

更新:好吧，我想我在阅读了一些内容后发现了问题，现在响应几乎是即时的，在 View 的通知中我已经将进程推回主线程，如下所示:

-(void)peerDidChangeStateWithNotification:(NSNotification *)notification{

        MCPeerID *peerID = [[notification userInfo] objectForKey:@"peerID"];
        NSString *peerDisplayName = peerID.displayName;
        MCSessionState state = [[[notification userInfo] objectForKey:@"state"] intValue];

        if (state != MCSessionStateConnecting) {

            if (state == MCSessionStateConnected) {
                // add the user
                [arrConnectedDevices addObject:peerDisplayName];
            }
            else if (state == MCSessionStateNotConnected){

                // do we have connections
                if ([arrConnectedDevices count] > 0) {
                    int indexOfPeer = [arrConnectedDevices indexOfObject:peerDisplayName];
                    [arrConnectedDevices removeObjectAtIndex:indexOfPeer];
                }
            }
        }

    // push to main queue for speedy response
    dispatch_async(dispatch_get_main_queue(), ^(void) {

        [collView reloadData];

        BOOL peersExist = ([[appDelegate.mcManager.session connectedPeers] count] == 0);
        NSLog(@"PEER COUNT IS %lu",(unsigned long)[[appDelegate.mcManager.session connectedPeers] count]);
        [disconnectButton setEnabled:!peersExist];

        if ([disconnectButton isEnabled]) {
            [disconnectButton setBackgroundColor:[UIColor colorWithRed:(51/255.0) green:(202/255.0) blue:(168/255.0) alpha:1.0]];
        }
        else{
            [disconnectButton setBackgroundColor:[UIColor colorWithRed:(107/255.0) green:(107/255.0) blue:(107/255.0) alpha:1.0]];
        }

    });

}

希望这对遇到问题的任何人有所帮助。

关于ios - 为什么 Multipeer Connectivity 这么慢？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24765639/