Question

我正在尝试以Central和Peripheral模式启动BLE。现在为了简单起见，使用硬编码变量我想我已根据文档实现了所有内容。

我可以使用Android智能手机检查周边模式是否正常工作（api-19，不支持外设模式）。例如，当我使用MyBeacon应用程序时，iPhone会正确显示。

但是当我在我的应用程序中运行此代码时，它不显示：

以下是.h：

#import <RCTBridgeModule.h>
#import <RCTEventEmitter.h>
@import CoreBluetooth;
@import QuartzCore;

@interface BTManager : RCTEventEmitter <RCTBridgeModule, CBCentralManagerDelegate, CBPeripheralManagerDelegate, CBPeripheralDelegate>

@property (nonatomic, strong) CBCentralManager *centralManager;
@property (nonatomic, strong) CBPeripheralManager *peripheralManager;
@property (nonatomic, strong) CBMutableCharacteristic *transferCharacteristic;

@end

.m：

#import "BTManager.h"

@implementation BTManager

RCT_EXPORT_MODULE();

- (NSArray<NSString *> *)supportedEvents
{
  return @[@"BTManagerDeviceFound", @"BTManagerStatus"];
}

- (void)viewDidLoad
{
  CBCentralManager *centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
  self.centralManager = centralManager;
  CBPeripheralManager *peripheralManager = [[CBPeripheralManager alloc] initWithDelegate:self queue:nil];
  self.peripheralManager = peripheralManager;
}

RCT_EXPORT_METHOD(start:(NSDictionary *)options)
{

  [self.centralManager scanForPeripheralsWithServices:nil options:nil];

  self.transferCharacteristic = [[CBMutableCharacteristic alloc] initWithType:[CBUUID UUIDWithString:@"EB6727C4-F184-497A-A656-76B0CDAC633A"] properties:CBCharacteristicPropertyRead value:nil permissions:CBAttributePermissionsReadable];

  CBMutableService *transferService = [[CBMutableService alloc] initWithType:[CBUUID UUIDWithString:@"EB6727C4-F184-497A-A656-76B0CDAC633A"] primary:YES];

  transferService.characteristics = @[self.transferCharacteristic];

  [self.peripheralManager addService:transferService];

  [self.peripheralManager startAdvertising:@{ CBAdvertisementDataServiceUUIDsKey : @[[CBUUID UUIDWithString:@"FB694B90-F49E-4597-8306-171BBA78F846"]] }];

  NSLog(@"Started");
}

- (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral {
  // log peripheralManager state
  NSLog(@"peripheralManagerDidUpdateState peripheral %@", peripheral);
}

- (void)peripheralManager:(CBPeripheralManager *)peripheral didAddService:(CBService *)service error:(NSError *)error
{
  // log centralManager state
  NSLog(@"peripheralManager didAddService peripheral %@", peripheral);
  NSLog(@"peripheralManager didAddService service %@", service);
  NSLog(@"peripheralManager didAddService error %@", error);
}

- (void)peripheralManagerDidStartAdvertising:(CBPeripheralManager *)peripheral error:(NSError *)error
{
  NSLog(@"peripheralManagerDidStartAdvertising peripheral %@", peripheral);
  NSLog(@"peripheralManagerDidStartAdvertising error %@", error);
}

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
  [self sendEventWithName:@"BTManagerDeviceFound" body:advertisementData];
}

- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
  NSLog(@"centralManagerDidUpdateState central %@", central);
}

RCT_EXPORT_METHOD(stop:(NSDictionary *)options)
{
  // remove all related processes, send event to js
  [self sendEventWithName:@"BTManagerStatus" body:@"details here"];
  //  [self.myCentralManager stopScan];
}

@end

除NSLog(@"Started");

外，上述所有事件侦听器均未触发

我有这个建议：

在相关主题上，确保无论代码创建和执行任何代码，都可以让对象存活足够长的时间以执行蓝牙操作。如果它超出范围或被垃圾收集，你将遇到同样的问题。

我不知道如何判断这是否属实。

此外，this tutorial正在使用此方法：

- (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral {
    if (peripheral.state != CBPeripheralManagerStatePoweredOn) {
        return;
    }

    if (peripheral.state == CBPeripheralManagerStatePoweredOn) {
        self.transferCharacteristic = [[CBMutableCharacteristic alloc] initWithType:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID] properties:CBCharacteristicPropertyNotify value:nil permissions:CBAttributePermissionsReadable];

        CBMutableService *transferService = [[CBMutableService alloc] initWithType:[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID] primary:YES];

        transferService.characteristics = @[_transferCharacteristic];

        [_peripheralManager addService:transferService];
    }
}

...但docs不包含任何与此CBPeripheralManagerStatePoweredOn左右相关的内容。这篇文章已有4年历史了，所以现在可能甚至都不相关。

哦，是的，而且我对Objective-c几乎不熟悉，所以那里的错误可能非常简单。

感谢您阅读，直到这里：）

更新1

显然，viewDidLoad永远不会被启动。因此，我已将代码从start方法移至代码，并将start中的代码移至...DidUpdateState方法，如@LarsBlumberg建议的那样。

#import "BTManager.h"
#import <React/RCTLog.h>

@implementation BTManager

RCT_EXPORT_MODULE();

- (NSArray<NSString *> *)supportedEvents
{
  return @[@"BTManagerDeviceFound", @"BTManagerStatus"];
}

RCT_EXPORT_METHOD(start:(NSDictionary *)options)
{
  RCTLogInfo(@"Start?");
  CBCentralManager *centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil options:@{CBCentralManagerOptionShowPowerAlertKey: @(YES)}];
  self.centralManager = centralManager;
  CBPeripheralManager *peripheralManager = [[CBPeripheralManager alloc] initWithDelegate:self queue:nil];
  self.peripheralManager = peripheralManager;
  RCTLogInfo(@"Started");
}

- (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral {
  // log peripheralManager state
  RCTLogInfo(@"peripheralManagerDidUpdateState peripheral %ld", (long)peripheral.state);
  if (peripheral.state != CBPeripheralManagerStatePoweredOn) {
    RCTLogInfo(@"Peripheral is not powered on");
    return;
  }
  self.transferCharacteristic = [[CBMutableCharacteristic alloc] initWithType:[CBUUID UUIDWithString:@"EB6727C4-F184-497A-A656-76B0CDAC633A"] properties:CBCharacteristicPropertyRead value:nil permissions:CBAttributePermissionsReadable];

  CBMutableService *transferService = [[CBMutableService alloc] initWithType:[CBUUID UUIDWithString:@"EB6727C4-F184-497A-A656-76B0CDAC633A"] primary:YES];

  transferService.characteristics = @[self.transferCharacteristic];

  [peripheral addService:transferService];

  NSDictionary *advertisingData = @{CBAdvertisementDataLocalNameKey : @"yphone", CBAdvertisementDataServiceUUIDsKey : @[[CBUUID UUIDWithString:@"EBA38950-0D9B-4DBA-B0DF-BC7196DD44FC"]]};
  [peripheral startAdvertising:advertisingData];
}

- (void)peripheralManager:(CBPeripheralManager *)peripheral didAddService:(CBService *)service error:(NSError *)error
{
  // log centralManager state
  RCTLogInfo(@"peripheralManager didAddService peripheral %@", peripheral);
  RCTLogInfo(@"peripheralManager didAddService service %@", service);
  RCTLogInfo(@"peripheralManager didAddService error %@", error);
}

- (void)peripheralManagerDidStartAdvertising:(CBPeripheralManager *)peripheral error:(NSError *)error
{
  RCTLogInfo(@"peripheralManagerDidStartAdvertising peripheral %@", peripheral);
  RCTLogInfo(@"peripheralManagerDidStartAdvertising error %@", error);
}

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
  [self sendEventWithName:@"BTManagerDeviceFound" body:advertisementData];
}

- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
  RCTLogInfo(@"centralManagerDidUpdateState central %ld", (long)central.state);
  // if (central.state == CBCentralManagerStatePoweredOff) {
  //   UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Error" message: @"Please turn on Bluetooth in Settings" delegate: nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
  //   [alert show]; 
  // }
  if (central.state != CBCentralManagerStatePoweredOn) {
    RCTLogInfo(@"Central is not powered on");
    return;
  }
  [central scanForPeripheralsWithServices:nil options:nil];
}

RCT_EXPORT_METHOD(stop:(NSDictionary *)options)
{
  // remove all related processes, send event to js
  [self sendEventWithName:@"BTManagerStatus" body:@"details here"];
  //  [self.myCentralManager stopScan];
}

@end

现在一切顺利，直到状态更新。 central.state和peripheral.state都返回4，而CB...ManagerStatePoweredOn等于5。如何使其等于5？应用程序请求访问bt，但iphone没有启用它。当它手动启用时，一切似乎都运行良好。

Answer 1

您可能过早地将服务transferService添加到外围设备管理器中，您也可能过早地开始播放广告。

您需要等待，直到peripheralManagerDidUpdateState报告外围经理的状态已达到CBPeripheralManagerStatePoweredOn。

这就是说，您可以将代码从RCT_EXPORT_METHOD(start:(NSDictionary *)options)移到空peripheralManagerDidUpdateState实现中。

或者，如果您只想向peripheralManager添加服务，然后在有人调用您的start方法（看起来您正在创建React Native绑定？）时开始做广告，请确保self.peripheralManager.state方法中CBPeripheralManagerStatePoweredOn为start。但是，这需要start（您的React Native JS代码）的调用者不要过早调用此方法。

RCT_EXPORT_METHOD(start:(NSDictionary *)options)
{
  NSLog(@"Start?");
  if (self.peripheralManager.state != CBPeripheralManagerStatePoweredOn) {
      NSLog(@"Peripheral is not powered on");
      return;
  }
  if (self.centralManager.state != CBCentralManagerStatePoweredOn) {
      NSLog(@"Central is not powered on");
      return;
  }
  NSLog(@"OK, peripheral and central are both powered on");
  [self.centralManager scanForPeripheralsWithServices:nil options:nil];

  self.transferCharacteristic = [[CBMutableCharacteristic alloc] initWithType:[CBUUID UUIDWithString:@"EB6727C4-F184-497A-A656-76B0CDAC633A"] properties:CBCharacteristicPropertyRead value:nil permissions:CBAttributePermissionsReadable];

  CBMutableService *transferService = [[CBMutableService alloc] initWithType:[CBUUID UUIDWithString:@"EB6727C4-F184-497A-A656-76B0CDAC633A"] primary:YES];

  transferService.characteristics = @[self.transferCharacteristic];

  [self.peripheralManager addService:transferService];

  [self.peripheralManager startAdvertising:@{ CBAdvertisementDataServiceUUIDsKey : @[[CBUUID UUIDWithString:@"FB694B90-F49E-4597-8306-171BBA78F846"]] }];

  NSLog(@"Started");
}

同样，如果外围设备具有“开机”状态，则只能使用centralManager开始扫描。

Answer 2

显然，无法以编程方式在iOS上打开蓝牙，也无法以编程方式立即进行配对。

但是，我们可以通过RCT_EXPORT_METHOD（开始：（NSDictionary *）选项）方法，通过警报启用用户来打开蓝牙。

if(peripheralManager.state < CBPeripheralManagerStatePoweredOn){
{
     //Show alert to user to turn on the Bluetooth and it will go to 
       peripheralManagerDidUpdateState when user turn it on.
}
else
{
     //You can continue setting up the data.
}

iOS / Objective-C：外围模式下的BLE不起作用

更新1

2 个答案: