CoreBluetooth [警告] 未知错误：2

Question

我正在 iOS6 中开发一个 BLE 应用程序。在设置为通知状态后，当我在某个特性上调用 readValueForCharacteristic 时，我得到了 CoreBluetooth[WARNING] Unknown error: 2。

- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error`

The delegate callback gets called with an unknown error from NSLog: `Error updating value for characteristic Unknown (<fef2>) error: Error Domain=CBErrorDomain Code=0 "Unknown error." UserInfo=0x1dd3b7e0 {NSLocalizedDescription=Unknown error.}

请给点建议。

Answer 1

据我所知，您无法读取设置为通知的特征的值。

您需要“订阅”该特性的通知：

[peripheral setNotifyValue:YES forCharacteristic:characteristic];

然后可以在您的委托方法中读取该值：

- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error

iOS 的 BLE 文档在这方面做得很差。