Android Bluetooth之BluetoothChat分析

本篇主要是简单分析下Android官方demo: android-BluetoothChat

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主要分析如下文件：

• AndroidManifest.xml
• DeviceListActivity.java
• BluetoothChatFragment.java
• BluetoothChatService.java

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// AndroidManifest.xml

++ 蓝牙通信权限和蓝牙发现或设置权限 ++

    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    <uses-permission android:name="android.permission.BLUETOOTH"/>

// DeviceListActivity.java

++ 获取BluetoothAdapter 实例，注册设备发现接听广播以及获取已配对设备列表 ++

/**

* Member fields

*/

private BluetoothAdapter mBtAdapter;

@Override

protected void onCreate(Bundle savedInstanceState) {

    ......

    // Register for broadcasts when a device is discovered
    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
    this.registerReceiver(mReceiver, filter);

    // Register for broadcasts when discovery has finished
    filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
    this.registerReceiver(mReceiver, filter);

    // Get the local Bluetooth adapter
    mBtAdapter = BluetoothAdapter.getDefaultAdapter();

    // Get a set of currently paired devices
    Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
    ......

}

++ 启动检测周围蓝牙设备 ++

    /**
     * Start device discover with the BluetoothAdapter
     */
    private void doDiscovery() {
        Log.d(TAG, "doDiscovery()");

        // Indicate scanning in the title
        setProgressBarIndeterminateVisibility(true);
        setTitle(R.string.scanning);

        // Turn on sub-title for new devices
        findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);

        // If we're already discovering, stop it
        if (mBtAdapter.isDiscovering()) {
            mBtAdapter.cancelDiscovery();
        }

        // Request discover from BluetoothAdapter
        mBtAdapter.startDiscovery();
    }

++ 接收已发现的设备 ++

    /**
     * The BroadcastReceiver that listens for discovered devices and changes the title when
     * discovery is finished
     */
    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // If it's already paired, skip it, because it's been listed already
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
                }
                // When discovery is finished, change the Activity title
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                setProgressBarIndeterminateVisibility(false);
                setTitle(R.string.select_device);
                if (mNewDevicesArrayAdapter.getCount() == 0) {
                    String noDevices = getResources().getText(R.string.none_found).toString();
                    mNewDevicesArrayAdapter.add(noDevices);
                }
            }
        }
    };

//BluetoothChatFragment.java

++ 打开蓝牙 ++

    @Override
    public void onStart() {
        super.onStart();
        // If BT is not on, request that it be enabled.
        // setupChat() will then be called during onActivityResult
        if (!mBluetoothAdapter.isEnabled()) {
            Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
            // Otherwise, setup the chat session
        } else if (mChatService == null) {
            setupChat();
        }
    }

++ 初始化UI，并创建后台chat Service ++

    /**
     * Set up the UI and background operations for chat.
     */
    private void setupChat() {
        Log.d(TAG, "setupChat()");

        // Initialize the array adapte