Android蓝牙应用程序开发的基本步骤

来源：互联网发布：异星工厂物流网络编辑：程序博客网时间：2024/05/02 04:28

在Android系统中，开发蓝牙应用程序的基本步骤如下：

1.设置权限
在文件AndroidManifest.xml中声明使用蓝牙的权限，代码如下：

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

2.启动蓝牙

BluetoothAdapter mBuletoothAdapter = BuletoothAdapter.getDefaultAdapter();if(mBuletoothAdapter == null){    //表明此手机不支持蓝牙    return;}if(!mBluetoothAdapter.isEnabled()){    //蓝牙未开启，则开启蓝牙    Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);    startActivityForResult(enableIntent, REQUEST_ENABLE_BT);}//......public void onActivityResult(int requestCode, int resultCode, Intent data){    if(requestCode == REQUEST_ENABLE_BT){        if(requestCode == RESULT_OK){            //蓝牙已经开启        }    }}

3.发现蓝牙设备
(1)首先使本机蓝牙处于可见状态（即处于易被搜索到的状态），便于其他设备发现本机蓝牙，演示代码如下：

//使本机蓝牙在300秒内可被搜索private void ensureDiscoverable() {    if(mBuletoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {        Intent  discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);        discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DRATION, 300);        startActivity(discoverableIntent);    }}

(2)然后查找已经配对的蓝牙设备，即以前已经配对过的设备，演示代码如下：

Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();if(pairedDevices.size() > 0) {    findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);    for(bluetoothDevice device : pairedDevices){        //device.getName() +" "+ device.getAddress());    }} else {    mPairedDeviceArrayAdapter.add("没有找到已配对的设备");}

(3)最后通过 mBluetoothAdapter.startDiscovery() 方法来搜索设备，在此需要注册一个 BroadcastReceiver 来获得这个搜索结果。即先注册再获取信息，然后进行处理。演示代码如下：

//注册，当一个设备被发现时调用onReceiveIntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);    this.registerReceiver(mReceiver, filter);//当搜索结束后调用onReceivefilter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);    this.registerReceiver(mReceiver, filter);//......private BroadcastReceiver mReceiver = new BroadcastReceiver() {    @Override    public void onReceive(Context context, Intent intent) {        String action = intent.getAction();        if(BluetoothDevice.ACTION_FOUND.equals(action)) {            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);            //已经配对过的则跳过            if (device.getBondState() != BluetoothDevice.BOND_BONDED) {                mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress()); //保存设备地址与名字            }        } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {            //搜索结束            if(mNewDevicesArrayAdapter.getCount() == 0) {                mNewDevicesArrayAdapter.add("没有搜索到设备");            }        }    }};

4.建立连接
当查找到蓝牙设备后，接下来需要建立本机与其他设备之间的连接。一般在使用本机搜索其他蓝牙设备时，本机可以作为一个服务端来接收其他设备的连接。启动一个服务器端的线程，死循环等待客户端的连接，这与ServerSocket极为相似，此线程在准备连接之前启动。演示代码如下：

//UUID可以看做一个端口号private static final UUID MY_UUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");//像一个服务器一样时刻监听是否有建立连接    private class AcceptThread extends Thread {        private BluetoothServerSocket serverSocket;        public AcceptThread(boolean secure) {            BluetoothServerSocket temp = null;            try{                temp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME_INSECURE, MY_UUID);            }            catch (IOException e){                Log.e("app", "listen() failed", e);            }            serverSocket = temp;        }        public void run() {            BluetoothSocket socket = null;            while(true){                try{                    socket = serverSocket.accept();                }                catch (IOException e){                    Log.e("app", "accept() failed", e);                    break;                }            }            if(socket != null){                //此时可以新建一个数据交换线程，把此socket传进去            }        }        //取消监听        public void cancel() {            try{                serverSocket.close();            }            catch (IOException e){                Log.e("app", "Scoket Type", + socketType + "close() of server failed", e);            }        }    }

5.交换数据
当搜索到蓝牙设备后，接下来可以获取设备的地址，通过此地址获取一个BluetoothDevice对象，可以将其看做一个客户端，通过对象device.createRfcommSocketTo ServiceRecord(MY_UUID)同一个UUID可与服务器建立连接获取另一个socket对象。因为此服务端与客户端各有一个socket对象，所以此时它们可以相互交换数据，演示代码如下：

//另一个设备去连接本机，相当于客户端private class ConnectThread extends Thread{    private BluetoothSocket socket;    private BluetoothDevice device;    public ConnectThread(BluetoothDevice device, boolean secure){        this.device = device;        BluetoothSocket tmp = null;        try{            tmp = device.createRfcommSocketToServiceRecord(MY_UUID_SECURE);        }        catch (IOException e){            Log.e("app", "create() failed", e);        }    }    public void run(){        mBluetoothAdapter.cancelDiscovery();    //取消设备查找        try{            socket.connect();        }        catch (IOException e){            try{                socket.close();            }            catch (IOException e1){                Log.e("app", "unable to close() " + " socket during connection failure", e1);            }            connectionFailed(); //连接失败            return;        }        //此时可以新建一个数据交换线程，把此socket传进去    }    public void cancel() {        try{            socket.close();        }        catch (IOException e){            Log.e("app", "close() of connect socket failed", e);        }    }}

6.建立数据通信线程
这一阶段的任务是读取通信数据，演示代码如下：

//建立连接后，进行数据通信的线程private class ConnectedThread extends Thread {    private BluetoothSocket socket;    private InputStream inStream;    private OutputStream outStream;    public ConnectedThread(BluetoothSocket socket){        this.socket = socket;        try{            //获得输入、输出流            inStream = socket.getInputStream();            outStream = socket.getOutputStream();        }        catch (IOException e){            Log.e("app", "temp sockets not created", e);        }    }    public void run() {        byte[] buff = new byte[1024];        int len = 0;        //读数据需要不断监听，写数据不需要        while(true){            try{                len = inStream.read(buff);                //把读取到的数据发送给UI进行显示                Message msg = handler.obtainMessage(BluetoothChat.MESSAGE_READ, len, -1, buff);                msg.sendToTarget();            }            catch (IOException e){                Log.e("app", "disconnected", e);                connectionLost();   //失去连接                start();            //重新启动服务器                break;            }        }    }    public void write(byte[] buffer) {        try        {            outStream.write(buffer);            handler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer).sendToTarget();        }        catch (IOException e)        {            Log.e("app", "Exception during write", e);        }    }    public void cancle() {        try{            socket.close();        }        catch (IOException e){            Log.e("app", "close() of connect socket failed", e);        }    }}

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