android BLE 4.0 setCharacteristicNotification接收不到数据

Posted 2022-12-11 持续学习刻意练习

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问题描述：最近在开发 android BLE 读写数据
但是向设备写数据很顺利，但是在接收设备传来的数据时，死活接收不到。

   /** 
     * Enables or disables notification on a give characteristic. 
     * 
     * @param characteristic Characteristic to act on. 
     * @param enabled        If true, enable notification.  False otherwise. 
     */  
    public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,  
                                              boolean enabled)   
        if (mBluetoothAdapter == null || mBluetoothGatt == null)   
            Log.w(TAG, "BluetoothAdapter not initialized");  
            return;  
          
        mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);  

    

上面这样写是收不到数据的，主要是少加了 mBluetoothGatt.writeDescriptor(descriptor);

下面是修改后的代码：

/** 
      * Enables or disables notification on a give characteristic. 
      * 
      * @param characteristic Characteristic to act on. 
      * @param enabled        If true, enable notification.  False otherwise. 
      */  
     public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,  
                                               boolean enabled)   
         if (mBluetoothAdapter == null || mBluetoothGatt == null)   
             Log.w(TAG, "BluetoothAdapter not initialized");  
             return;  
           
 //        mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);  
         boolean isEnableNotification =  mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);  
         if(isEnableNotification)   
             List<BluetoothGattDescriptor> descriptorList = characteristic.getDescriptors();  
             if(descriptorList != null && descriptorList.size() > 0)   
                 for(BluetoothGattDescriptor descriptor : descriptorList)   
                     descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);  
                     mBluetoothGatt.writeDescriptor(descriptor);  
                   
               
           
     

如果不是这种情况接收不到数据就是另外一种可能了characteristic 的 uuid 设置不对，
你可以看下 boolean isEnableNotification = mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
返回的是false 还是true。

本位转载自：http://347563186.iteye.com/blog/2331399