CoreBluetooth 状态保存：恢复 CBCentralManager 的正确方法

Question

当应用由于状态保存事件而获得选项午餐时，从 AppDelegate 恢复 CBCentralManager 的正确方法是什么？

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // The system provides the restoration identifiers only for central managers that had active or pending peripheral connections or were scanning for peripherals.
    NSArray * centralManagerIdentifiers = launchOptions[UIApplicationLaunchOptionsBluetoothCentralsKey];

    if (centralManagerIdentifiers != nil) {
        for (int i=0; i<[centralManagerIdentifiers count]; i++) {
            NSString * identifier = [centralManagerIdentifiers objectAtIndex:i];
            NSLog(@"bluetooth central key identifier %@", identifier);
            // here I expect to re-instatiate the CBCentralManager but not sure how and if this is the best place..
        }
    }

    // Override point for customization after application launch.
    return YES;
}

Answer 1

当您获得标识符列表时，您必须遍历此列表并为每个标识符初始化 CBCentralManager 的实例。列表包含NSStrings 个对象。

NSArray *centralManagerIdentifiers = launchOptions[UIApplicationLaunchOptionsBluetoothCentralsKey];

for (NSString *centralManagerIdentifier in centralManagerIdentifiers) {
    CBCentralManager *centralManager = [[CBCentralManager alloc] initWithDelegate:self
                                                                            queue:nil
                                                                          options:@{CBCentralManagerOptionRestoreIdentifierKey: centralManagerIdentifier}];

    [self.cenralManagers addObject:centralManager];
}

更多细节请参考核心蓝牙编程指南中的State Preservation and Restoration。