iOS蓝牙APP常驻后台

来源：cnblogs　　作者：yuyuyu37　　时间：2018/11/20 17:13:59　　对本文有异议

iOS蓝牙类APP常驻后台的实现方法，经过在苹果开发者论坛询问，以及查看苹果开发者文档，最后得出正确的方法为：

1.设置plist，蓝牙权限

2.到target-capabilities-background modes中打开use Bluetooth LE accessories选项

3.创建central manager时设置restore identifier

_bluetoothmanager = [[CBCentralManager alloc] initWithDelegate:self queue:centralQueue options:@{CBCentralManagerOptionRestoreIdentifierKey : CardReadingServiceManagerRestoreIdentifier}];

4.appdelegate的didfinishlaunching方法中，如果检测到对应的key就重新创建Bluetooth manager

for (NSString *blue in centralManagerIdentifiers) {
     if ([blue isEqualToString:CardReadingServiceManagerRestoreIdentifier]) {
           [CardReadingService getInstance].bluetoothmanager = nil;
           [[CardReadingService getInstance] bluetoothmanager];
           break;
        }
   }

5.实现Bluetooth central delegate的willRestoreState方法，开启扫描

- (void)centralManager:(CBCentralManager *)central willRestoreState:(NSDictionary<NSString *,id> *)dict {
    [self startScan];
    [self startAccleerometer];
}