Android低功耗蓝牙升级 5.0以上的BLE开发

太过爱你忘了你带给我的痛 2022-06-15 10:24 853阅读 0赞

蓝牙4.0分为标准蓝牙和低功耗蓝牙（BLE），标准蓝牙就是手机上用的那种，低功能耗蓝牙由于其具有最大化的待机时间、快速连接和低峰值的发送和接收特性，被广泛用于智能手表、智能手环等可穿戴设备上。在安卓4.3之前，安卓平台上的BLE开发相当难搞，好在谷歌在4.3之后发布了官方的API。在安卓5.0之后又引入了新的API，原来的API已经被废弃。在新的系统里采用旧API开发的APP仍可使用，但采用新API开发的APP只能在LOLLIPOP即安卓5.0及其以后的版本使用。

标准蓝牙的的开发和BLE不同。标准蓝牙连接里有两个角色一个是客户端一个是服务器，当客户端搜索到蓝牙服务器后并与之配对后，才能通过UUID（这个是唯一的，服务器端必须与客户端一致）建立socket，然后使用流像文件读写和网络通信那样传输数据就行了。在BLE里，变成了中心设备（central）和外围设备（peripheral），中心设备就是你的手机，外围设备就是智能手环一类的东西。开发BLE的应用都得遵守Generic Attribute Profile (GATT)，一个BLE蓝牙设备包含多个service，每个service又包含多个characteristic。每个characteristic有一个value和多个descriptor，通过characteristic中心设备与外围设备进行通信。descriptor顾名思义，包含了BLE设备的一些信息。不同service、characteristic和descriptor都有各自己唯一的UUID。想要跟BLE设备通信，首先通过UUID获取目标服务，然后再通过UUID获取characteristic，charateristic起着载体的作用，通过writeCharacteristic()和readCharacteristic()，可以写入和读出信息。每个characteristic都有一些自己的属性，其中在property里，说明了该characteristic的属性，例如READ|WRITE|WRITE\_NO\_RESPONSE|NOTIFY。

以下是关键代码：

1.首先，在AndroidManifest.xml里加入

<uses-feature android:name="android.bluetooth.le" android:required="true"/> //Android 5.0之前是android.hardware.bluetooth_le
        <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
        <uses-permission android:name="android.permission.BLUETOOTH"/>

使用新API时，最好在调用方法前判断下系统版本，否则会出现意想不到的错误。

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    　　...
    }

2.获取BluetoothAdapter。

![复制代码][copycode.gif]

BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(BLUETOOTH_SERVICE);//这里与标准蓝牙略有不同
     BluetoothAdapter bluetoothAdapter = bluetoothManager.getAdapter();
    　　/*隐式打开蓝牙*/
    　　if (!bluetoothAdapter.isEnabled()) {
    　　　　bluetoothAdapter.enable();
    　　}

![复制代码][copycode.gif]

3.然后获取BluetoothLeScanner，通过startScan()方法扫描周围的BLE设备。当搜索到目标设备或者搜索一定时间后通过BluetoothScanner的stopScan()方法停止搜索。

BluetoothLeScanner scanner = bluetoothAdapter.getBluetoothLeScanner();
    scanner.startScan(leCallback);

leCallback是一个回调函数，通过onScanResult()把每次搜索到的设备添加到本地。leCallback还有一个方法onBatchScanResults(),按理说应该是批量处理搜索到的结果，但是不知道为什么在我这里无法调用。

![复制代码][copycode.gif]

leCallback = new ScanCallback() {
                    @Override
                    public void onScanResult(int callbackType, ScanResult result) {
                        super.onScanResult(callbackType, result);
                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                            BluetoothDevice device = result.getDevice();
                            if (!devices.contains(device)) {  //判断是否已经添加
                                devices.add(device);
                            }
                            deviceAdapter.notifyDataSetChanged();
                        }
                    }
    
                    @Override
                    public void onScanFailed(int errorCode) {
                        super.onScanFailed(errorCode);
                        Log.e("搜索失败");
                    }
                };

![复制代码][copycode.gif]

4.开始连接。

![复制代码][copycode.gif]

BluetoothGatt bluetoothGatt = device.connectGatt(MainActivity.this, false, new BluetoothGattCallback() {
    
                    @Override
                    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
                        if (newState == BluetoothProfile.STATE_CONNECTED) {   
                            gatt.discoverServices();　　　　　　　　　　//连接成功，开始搜索服务，一定要调用此方法，否则获取不到服务
                        }
                    }
    
                    @Override
                    public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
                          Log.e(TAG,gatt.getDevice().getName() + " write successfully");
                    }
    
                    @Override
                    public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
                        　　String value = UtilOnStr.parseBytesToHexString(characteristic.getValue());
                            Log.e(TAG,gatt.getDevice().getName() + " recieved " + value);
                    }
    
    　　　　　　　　@Override
        　　　　　　public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
           　　　　　　 　　String response = UtilOnStr.parseBytesToHexString(characteristic.getValue());
    　　　　　　　　　　　　　Log.e(TAG,  "The response is "+ response); 
            　　　　}
    
    });

![复制代码][copycode.gif]

5.写入和读取数据。

![复制代码][copycode.gif]

BluetoothGattService service = bluetoothGatt.getService(SERVICE_UUID);
    if(service != null) {
    　　characteristic = service.getCharacteristic(CHARACTERISTIC_UUID);
    　　if (characteristic !=null) {    
    　　　　bluetoothGatt.setCharacteristicNotification(characteristic, true);  //设置characteristic的通知，触发bluetoothGatt.onCharacteristicWrite()事件。
            characteristic.setValue(UtilOnStr.parseHexStringToBytes(value));
            bluetoothGatt.writeCharacteristic(characteristic);  
        }
    }

![复制代码][copycode.gif]

当连接上BLE设备后，调用discoveryServices()发现服务，通过SERVICE\_UUID获取目标service，如果service不为空，再通过CHARACTERISTIC\_UUID获取characteristic，借助characteristic写入指定值与BLE设备进行通信。这里要注意的是characteristic接收的是一个byte数组，而且读写的方法都是异步的。调用bluetoothGatt.readCharacteristic(characteristic)可读取BLE设备返回的值。bluetoothGatt的writeCharacteristic()方法会触发BluetoothGattCallback里的onCharacteristicWrite(),相应的，bluetoothGatt的readCharacteristic()方法会触发onCharacteristicRead()。

对中心设备与外围设备的传输数据的处理发生在onCharacteristicChanged()里，当characteristic写入了正确的数值后，会激活BLE设备，不时地返回数据。

当不知道BLE设备的service和characteristic的对应的UUID时，可以在回调函数里的onServicesDiscovered()方法里，通过BluetoothGatt的getServices()获得该设备所有的service，然后再调用service的getUuid()得到其UUID，同理通过service的getCharacteristics()可以得到每个service所有的characteristic和其UUID。然后一个个不厌其烦的尝试，找到正确的service和characteristic。

链接后官方的回调方法详解:

# BluetoothGattCallback #

`public abstract class BluetoothGattCallback`  
`extends Object```

<table style="font-size:14px; margin:1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:940px; padding:0px; font-family:Roboto,sans-serif; line-height:24px"> 
 <tbody> 
  <tr> 
   <td colspan="2" style="padding:0px; vertical-align:top; border:none; margin:0px; background-color:transparent"> <a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">java . lang . object</a></td> 
  </tr> 
  <tr> 
   <td style="padding:0px; vertical-align:top; border:none; margin:0px; width:2em; background-color:transparent"> <span style="margin-bottom:0px">↳</span></td> 
   <td colspan="1" style="padding:0px; vertical-align:top; border:none; margin:0px; background-color:transparent"> <span style="margin-bottom:0px">android.bluetooth.BluetoothGattCallback</span></td> 
  </tr> 
 </tbody> 
</table>

--------------------

这个抽象类是用于实现` BluetoothGatt`回调。

## 总结 ##

--------------------

<table style="font-size:14px; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; font-family:Roboto,sans-serif; line-height:24px; background-color:rgb(247,247,247)"> 
 <tbody> 
  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> <h3 style="color:inherit; font-size:undefined; line-height:inherit; font-weight:inherit; margin:0px; padding:0px"> 公共方法</h3> </th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onCharacteristicChanged</a>(<a style="color:rgb(3,155,229)" rel="nofollow">BluetoothGatt</a>&nbsp;gatt,<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;BluetoothGattCharacteristic</a>&nbsp;characteristic)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调通知由于远程触发特征。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onCharacteristicRead</a>(<a style="color:rgb(3,155,229)" rel="nofollow">BluetoothGatt</a>&nbsp;gatt,<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;BluetoothGattCharacteristic</a>&nbsp;characteristic, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调报告特点读操作的结果。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onCharacteristicWrite</a>(<a style="color:rgb(3,155,229)" rel="nofollow">BluetoothGatt</a>&nbsp;gatt,<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;BluetoothGattCharacteristic</a>&nbsp;characteristic, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调指示特点写操作的结果。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onConnectionStateChange</a>(<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">BluetoothGatt</a>&nbsp;gatt, int status, int newState)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调表明当关贸总协定端连接/断开连接从远程关贸总协定/服务器。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onDescriptorRead</a>(<a style="color:rgb(3,155,229)" rel="nofollow">BluetoothGatt</a>&nbsp;gatt,<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;BluetoothGattDescriptor</a>&nbsp;descriptor, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调报告描述符读操作的结果。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onDescriptorWrite</a>(<a style="color:rgb(3,155,229)" rel="nofollow">BluetoothGatt</a>&nbsp;gatt,<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;BluetoothGattDescriptor</a>&nbsp;descriptor, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调指示符写操作的结果。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onMtuChanged</a>(<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">BluetoothGatt</a>&nbsp;gatt, int mtu, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调表明MTU对于一个给定的设备连接已经改变了。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221)"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221)"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onPhyRead</a>(<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">BluetoothGatt</a>&nbsp;gatt, int txPhy, int rxPhy, int status)</code> <p style="margin-top:0px; margin-bottom:0px">回调触发的结果<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;readPhy()</a></code></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221)"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221)"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onPhyUpdate</a>(<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">BluetoothGatt</a>&nbsp;gatt, int txPhy, int rxPhy, int status)</code> <p style="margin-top:0px; margin-bottom:0px">回调触发的结果<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;setPreferredPhy(int, int, int)</a></code><span style="margin-bottom:0px">,或者由于远程设备改变了体育。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onReadRemoteRssi</a>(<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">BluetoothGatt</a>&nbsp;gatt, int rssi, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调报告的RSSI远程设备连接。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onReliableWriteCompleted</a>(<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">BluetoothGatt</a>&nbsp;gatt, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调时调用一个可靠写事务已经完成。</span></p> </td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">void</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style=""><a style="color:rgb(3,155,229)" rel="nofollow">onServicesDiscovered</a>(<a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">BluetoothGatt</a>&nbsp;gatt, int status)</code> <p style="margin-top:0px; margin-bottom:0px"><span style="margin-bottom:0px">回调时调用远程服务的列表,特性和描述符的远程设备更新,即发现了新的服务。</span></p> </td> 
  </tr> 
 </tbody> 
</table>

<table style="font-size:14px; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:940px; font-family:Roboto,sans-serif; line-height:24px; background-color:rgb(247,247,247)"> 
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   <th style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> <h3 style="color:inherit; font-size:undefined; line-height:inherit; font-weight:inherit; margin:0px; padding:0px"> 继承的方法</h3> </th> 
  </tr> 
  <tr> 
   <td colspan="2" style="padding:4px 12px 4px 0px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <a style="color:rgb(3,155,229)" rel="nofollow"><img height="34" src="https://developer.android.google.cn/assets/images/styles/disclosure_down.png" alt="" style="border:none; max-width:100%; vertical-align:middle; margin:0px; padding:0px 4px 4px 0px"></a>从类<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;java.lang.Object</a></code> 
    <div style="margin-bottom:0px; padding-left:12px"> 
     <div style="padding-left:12px"> 
     </div> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

## 公共构造函数 ##

--------------------

### BluetoothGattCallback ###

添加到 API级别18

BluetoothGattCallback ()

## 公共方法 ##

--------------------

### onCharacteristicChanged ###

添加到 API级别18

void onCharacteristicChanged (BluetoothGatt gatt, 
                    BluetoothGattCharacteristic characteristic)

回调通知由于远程触发特征。

### onCharacteristicRead ###

添加到 API级别18

void onCharacteristicRead (BluetoothGatt gatt, 
                    BluetoothGattCharacteristic characteristic, 
                    int status)

回调报告特点读操作的结果。

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
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   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGatt</code>:《关贸总协定》客户端调用<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;readCharacteristic(BluetoothGattCharacteristic)</a></code></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">characteristic</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGattCharacteristic</code><span style="margin-bottom:0px">:读取相关的远程设备的特点。</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;GATT_SUCCESS</a></code><span style="margin-bottom:0px">如果读操作成功完成。</span></td> 
  </tr> 
 </tbody> 
</table>

### onCharacteristicWrite ###

添加到 API级别18

void onCharacteristicWrite (BluetoothGatt gatt, 
                    BluetoothGattCharacteristic characteristic, 
                    int status)

回调指示特点写操作的结果。

如果调用这个回调而可靠的写事务过程中,特征的值代表了远程设备报告的价值。一个应用程序要比这个值到所需的值。如果值不匹配,应用程序必须中止可靠写事务。

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
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   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGatt</code>:《关贸总协定》客户端调用<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;writeCharacteristic(BluetoothGattCharacteristic)</a></code></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">characteristic</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGattCharacteristic</code><span style="margin-bottom:0px">:特点是写入相关的远程设备。</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:写操作的结果<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;GATT_SUCCESS</a></code><span style="margin-bottom:0px">如果操作成功。</span></td> 
  </tr> 
 </tbody> 
</table>

### onConnectionStateChange ###

添加到 API级别18

void onConnectionStateChange (BluetoothGatt gatt, 
                    int status, 
                    int newState)

回调表明当关贸总协定端连接/断开连接从远程关贸总协定/服务器。

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
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  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGatt</code><span style="margin-bottom:0px">:关贸总协定端</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:连接或断开连接操作的状态。<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;GATT_SUCCESS</a></code><span style="margin-bottom:0px">如果操作成功。</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">newState</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:返回新连接的状态。可以是其中一个<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;STATE_DISCONNECTED</a></code>或<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;STATE_CONNECTED</a></code></td> 
  </tr> 
 </tbody> 
</table>

### onDescriptorRead ###

添加到 API级别18

void onDescriptorRead (BluetoothGatt gatt, 
                    BluetoothGattDescriptor descriptor, 
                    int status)

回调报告描述符读操作的结果。

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
 <tbody> 
  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGatt</code>:《关贸总协定》客户端调用<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;readDescriptor(BluetoothGattDescriptor)</a></code></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">descriptor</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGattDescriptor</code><span style="margin-bottom:0px">:读取相关的远程设备的描述符。</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;GATT_SUCCESS</a></code><span style="margin-bottom:0px">如果读操作成功完成</span></td> 
  </tr> 
 </tbody> 
</table>

### onDescriptorWrite ###

添加到 API级别18

void onDescriptorWrite (BluetoothGatt gatt, 
                    BluetoothGattDescriptor descriptor, 
                    int status)

回调指示符写操作的结果。

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 <tbody> 
  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGatt</code>:《关贸总协定》客户端调用<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;writeDescriptor(BluetoothGattDescriptor)</a></code></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">descriptor</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGattDescriptor</code><span style="margin-bottom:0px">:描述符是writte相关的远程设备。</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:写操作的结果<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;GATT_SUCCESS</a></code><span style="margin-bottom:0px">如果操作成功。</span></td> 
  </tr> 
 </tbody> 
</table>

### onMtuChanged ###

添加到 API级别21

void onMtuChanged (BluetoothGatt gatt, 
                    int mtu, 
                    int status)

回调表明MTU对于一个给定的设备连接已经改变了。这个回调的触发` requestMtu(int)`函数,或在回应一个连接事件。

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
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  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGatt</code>:《关贸总协定》客户端调用<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;requestMtu(int)</a></code></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">mtu</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code><span style="margin-bottom:0px">:新MTU大小</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;GATT_SUCCESS</a></code><span style="margin-bottom:0px">如果MTU已经更改成功</span></td> 
  </tr> 
 </tbody> 
</table>

### onPhyRead ###

**Android O开发者预览版**

void onPhyRead (BluetoothGatt gatt, 
                    int txPhy, 
                    int rxPhy, 
                    int status)

回调触发的结果` readPhy()`

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
 <tbody> 
  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(245,186,21); font-weight:normal; background:rgb(245,186,21)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">BluetoothGatt</code><span style="margin-bottom:0px">:关贸总协定端</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">txPhy</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">int</code>:发射机PHY在使用。之一<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_1M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_2M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_CODED</a></code>.</td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">rxPhy</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">int</code>:接收机PHY在使用。之一<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_1M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_2M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_CODED</a></code>.</td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">int</code><span style="margin-bottom:0px">:操作的状态</span></td> 
  </tr> 
 </tbody> 
</table>

### onPhyUpdate ###

**Android O开发者预览版**

void onPhyUpdate (BluetoothGatt gatt, 
                    int txPhy, 
                    int rxPhy, 
                    int status)

回调触发的结果` setPreferredPhy(int, int, int)`,或者由于远程设备改变了体育。

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
 <tbody> 
  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(245,186,21); font-weight:normal; background:rgb(245,186,21)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">BluetoothGatt</code><span style="margin-bottom:0px">:关贸总协定端</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">txPhy</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">int</code>:发射机PHY在使用。之一<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_1M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_2M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_CODED</a></code>.</td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">rxPhy</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">int</code>:接收机PHY在使用。之一<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_1M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_2M</a></code>,<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;PHY_LE_CODED</a></code>.</td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(245,186,21)"> <code style="">int</code><span style="margin-bottom:0px">:操作的状态</span></td> 
  </tr> 
 </tbody> 
</table>

### onReadRemoteRssi ###

添加到 API级别18

void onReadRemoteRssi (BluetoothGatt gatt, 
                    int rssi, 
                    int status)

回调报告的RSSI远程设备连接。这个回调的触发` readRemoteRssi()`函数。

<table style="font-size:1em; margin:0.5em 1em 1em 0px; border-collapse:collapse; border-spacing:0px; border:0px; width:939px; background-color:rgb(247,247,247)"> 
 <tbody> 
  <tr> 
   <th colspan="2" style="padding:4px 12px; vertical-align:top; color:rgb(255,255,255); border:1px solid rgb(221,221,221); font-weight:normal; background-color:rgb(153,153,153)"> 参数</th> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">gatt</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">BluetoothGatt</code>:《关贸总协定》客户端调用<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;readRemoteRssi()</a></code></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">rssi</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code><span style="margin-bottom:0px">:远程设备的RSSI值</span></td> 
  </tr> 
  <tr> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">status</code></td> 
   <td style="padding:4px 12px; vertical-align:top; border:1px solid rgb(221,221,221); background-color:inherit"> <code style="">int</code>:<code style=""><a style="color:rgb(3,155,229); margin-bottom:0px" rel="nofollow">&nbsp;GATT_SUCCESS</a></code><span style="margin-bottom:0px">如果RSSI读成功</span></td> 
  </tr> 
 </tbody> 
</table>

### onReliableWriteCompleted ###

添加到 API级别18

void onReliableWriteCompleted (BluetoothGatt gatt, 
                    int status)

回调时调用一个可靠写事务已经完成。

### onServicesDiscovered ###

添加到 API级别18

void onServicesDiscovered (BluetoothGatt gatt, 
                    int status)

回调时调用远程服务的列表,特性和描述符的远程设备更新,即发现了新的服务。

[copycode.gif]: /images/20220615/ab5de7bdbccd41aaaa542e17088bbf69.png