你有什么想法解决我的问题吗？

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

    NSDictionary* dict = [[NSNetService dictionaryFromTXTRecordData:[service TXTRecordData]] retain];
    MyTreeNode *node = [[MyTreeNode alloc] initWithValue:[service name]];
    NSString* info = [self copyStringFromTXTDict:dict which:@"info"];
    if([info isEqualToString:@"child"]) { // info == null and dict == null??
        [treeNode addChild:node];
    }
    [info release];
    if (!moreComing) {
        [self sortAndUpdateUI];
    }
}