Question

我有一个使用BTLE连接到设备（arduino）的iOS应用程序。我的iPad iOS 7上的一切正常。升级到iOS 8后，CBCentralManager找不到任何外围设备。

- (void)startScanningForSupportedUUIDs
{
   [self.centralManager scanForPeripheralsWithServices:nil options:nil];

}

我不知道会出现什么问题。

Answer 1

我有解决方案，出于某种原因，在iOS 8中实例化CBManager后会有一些延迟。您需要在CBCentralManager打开时开始扫描，使用此方法：

-(void)centralManagerDidUpdateState:(CBCentralManager *)central{
switch (central.state) {
    case CBCentralManagerStatePoweredOff:
        NSLog(@"CoreBluetooth BLE hardware is powered off");
        break;
    case CBCentralManagerStatePoweredOn:
    {
        NSLog(@"CoreBluetooth BLE hardware is powered on and ready");
        NSArray         *uuidArray  = [NSArray arrayWithObjects:[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID], nil];
        NSDictionary    *options    = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:CBCentralManagerScanOptionAllowDuplicatesKey];
        [centralManager scanForPeripheralsWithServices:uuidArray options:options];
    }
        break;
    case CBCentralManagerStateResetting:
        NSLog(@"CoreBluetooth BLE hardware is resetting");
        break;
    case CBCentralManagerStateUnauthorized:
        NSLog(@"CoreBluetooth BLE state is unauthorized");
        break;
    case CBCentralManagerStateUnknown:
        NSLog(@"CoreBluetooth BLE state is unknown");
        break;
    case CBCentralManagerStateUnsupported:
        NSLog(@"CoreBluetooth BLE hardware is unsupported on this platform");
        break;
    default:
        break;
}

Answer 2

在IOS 7中，即使在CBCentralManager准备就绪之前，您也可以通过启动BLE扫描来逃避。在这种情况下，IOS 7过去常常发出警告 -

CoreBluetooth [API MISUSE]只能在开机状态下接受命令

使用IOS8 - 不再显示警告，扫描实际上没有启动。要解决此问题，请等待CBCentral打开电源 - 即等待CBCentral管理器进入“CBCentralManagerStatePoweredOn”状态，然后开始扫描。它适用于这种变化：）

iOS8和BTLE | CBCentralManager无法找到外围设备

2 个答案: