提供管理蓝牙功能的类，诸如扫描设备、连接设备以及管理设备间的数据传输。蓝牙 API 同时支持传统蓝牙和最新的低能耗蓝牙。
Provides classes that manage Bluetooth functionality, such as scanning for devices, connecting with devices, and managing data transfer between devices. The Bluetooth API supports both "Classic Bluetooth" and Bluetooth Low Energy.

更多有关传统蓝牙的信息，可以参考 Bluetooth 指南。更多低能耗蓝牙的资料可以查看 Bluetooth Low Energy (BLE) 指南。
For more information about Classic Bluetooth, see the Bluetooth guide. For more information about Bluetooth Low Energy, see the Bluetooth Low Energy (BLE) guide.

蓝牙 API 可以让应用做如下的事情：
The Bluetooth APIs let applications:

• 扫描其它蓝牙设备(包括 BLE 设备)。
  Scan for other Bluetooth devices (including BLE devices).
• 为成对儿的蓝牙设备查询本地蓝牙适配器。
  Query the local Bluetooth adapter for paired Bluetooth devices.
• 建立 RFCOMM 通道/套接字。
  Establish RFCOMM channels/sockets.
• 连接其它设备上的指定套接字。
  Connect to specified sockets on other devices.
• 与其它设备进行互传数据。
  Transfer data to and from other devices.
• 与低能耗蓝牙设备进行通信，诸如接近传感器，心率监测器，健康设备等等。
  Communicate with BLE devices, such as proximity sensors, heart rate monitors, fitness devices, and so on.
• 担当 GATT 客户端或服务端(BLE)。
  Act as a GATT client or a GATT server (BLE).

要使用这些 API 执行蓝牙通信的话，应用必须声明 BLUETOOTH 权限。一些附加的功能，诸如请求设备发现等，也需要声明权限 BLUETOOTH_ADMIN。 
To perform Bluetooth communication using these APIs, an application must declare the BLUETOOTH permission. Some additional functionality, such as requesting device discovery, also requires the BLUETOOTH_ADMIN permission.

注意：并不是所有的 Android 设备都提供蓝牙功能。
Note: Not all Android-powered devices provide Bluetooth functionality.