android Bluetooth程序設計

為了初始化一個與遠端設備的連接，需要先獲取代表該設備的一個BluetoothDevice對象。通過BluetoothDevice對象

來獲取BluetoothSocket並初始化連接，具體步驟：

使用BluetoothDevice對象裡的方法createRfcommSocketToServiceRecord(UUID)來獲取BluetoothSocket。UUID就是

匹配碼。然後，調用connect（）方法來。如果遠端設備接收了該連接，他們將在通信過程中共享RFFCOMM信道，

並且connect返回。

注意：conncet（）方法也是阻塞調用，一般建立一個獨立的線程中來調用該方法。在設備discover過程中不應該發起

連接connect（），這樣會明顯減慢速度以至於連接失敗。且數據傳輸完成只有調用close（）方法來關閉連接，這樣

可以節省系統內部資源。

private class ConnectThread extends Thread {  
    private final BluetoothSocket mmSocket;  
    private final BluetoothDevice mmDevice;  
   
    public ConnectThread(BluetoothDevice device) {  
        // Use a temporary object that is later assigned to mmSocket,  
        // because mmSocket is final  
        BluetoothSocket tmp = null;  
        mmDevice = device;  
   
        // Get a BluetoothSocket to connect with the given BluetoothDevice  
        try {  
            // MY_UUID is the app's UUID string, also used by the server code  
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);  
        } catch (IOException e) { }  
        mmSocket = tmp;  
    }  
   
    public void run() {  
        // Cancel discovery because it will slow down the connection  
        mBluetoothAdapter.cancelDiscovery();  
   
        try {  
            // Connect the device through the socket. This will block  
            // until it succeeds or throws an exception  
            mmSocket.connect();  
        } catch (IOException connectException) {  
            // Unable to connect; close the socket and get out  
            try {  
                mmSocket.close();  
            } catch (IOException closeException) { }  
            return;  
        }  
   
        // Do work to manage the connection (in a separate thread)  
        manageConnectedSocket(mmSocket);  
    }  
   
    /** Will cancel an in-progress connection, and close the socket */  
    public void cancel() {  
        try {  
            mmSocket.close();  
        } catch (IOException e) { }  
    }  
}  

9.管理連接（主要涉及數據的傳輸）

當設備連接上以後，每個設備都擁有各自的BluetoothSocket。就可以實現設備之間數據的共享了。

首先通過調用getInputStream()和getOutputStream()方法來獲取輸入輸出流。

然後通過調用read(byte[]) 和write(byte[]).方法來讀取或者寫數據。

實現細節：以為讀取和寫操作都是阻塞調用，需要建立一個專用線程來管理。 。

private class ConnectedThread extends Thread {  
    private final BluetoothSocket mmSocket;  
    private final InputStream mmInStream;  
    private final OutputStream mmOutStream;  
   
    public ConnectedThread(BluetoothSocket socket) {  
        mmSocket = socket;  
        InputStream tmpIn = null;  
        OutputStream tmpOut = null;  
   
        // Get the input and output streams, using temp objects because  
        // member streams are final  
        try {  
            tmpIn = socket.getInputStream();  
            tmpOut = socket.getOutputStream();  
        } catch (IOException e) { }  
   
        mmInStream = tmpIn;  
        mmOutStream = tmpOut;  
    }  
   
    public void run() {  
        byte[] buffer = new byte[1024];  // buffer store for the stream  
        int bytes; // bytes returned from read()  
   
        // Keep listening to the InputStream until an exception occurs  
        while (true) {  
            try {  
                // Read from the InputStream  
                bytes = mmInStream.read(buffer);  
                // Send the obtained bytes to the UI activity  
                mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)  
                        .sendToTarget();  
            } catch (IOException e) {  
                break;  
            }  
        }  
    }  
   
    /* Call this from the main activity to send data to the remote device */  
    public void write(byte[] bytes) {  
        try {  
            mmOutStream.write(bytes);  
        } catch (IOException e) { }  
    }  
   
    /* Call this from the main activity to shutdown the connection */  
    public void cancel() {  
        try {  
            mmSocket.close();  
        } catch (IOException e) { }  
    }  
}  

10. 權限設置

操作藍牙權限:

例子程序：

main.xml

package com.testBlueTooth;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.ToggleButton;

public class testBlueTooth extends Activity {
    static final String SPP_UUID = "00001101-0000-1000-8000-00805F9B34FB";

    Button btnSearch, btnDis, btnExit;

    ToggleButton tbtnSwitch;

    ListView lvBTDevices;

    ArrayAdapter adtDevices;

    List lstDevices = new ArrayList();

    BluetoothAdapter btAdapt;

    public static BluetoothSocket btSocket;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // Button 設置
        btnSearch = (Button) this.findViewById(R.id.btnSearch);
        btnSearch.setOnClickListener(new ClickEvent());
        btnExit = (Button) this.findViewById(R.id.btnExit);
        btnExit.setOnClickListener(new ClickEvent());
        btnDis = (Button) this.findViewById(R.id.btnDis);
        btnDis.setOnClickListener(new ClickEvent());

        // ToogleButton設置
        tbtnSwitch = (ToggleButton) this.findViewById(R.id.tbtnSwitch);
        tbtnSwitch.setOnClickListener(new ClickEvent());

        // ListView及其數據源 適配器
        lvBTDevices = (ListView) this.findViewById(R.id.lvDevices);
        adtDevices = new ArrayAdapter(testBlueTooth.this,
                android.R.layout.simple_list_item_1, lstDevices);
        lvBTDevices.setAdapter(adtDevices);
        lvBTDevices.setOnItemClickListener(new ItemClickEvent());

        btAdapt = BluetoothAdapter.getDefaultAdapter();// 初始化本機藍牙功能

        if (btAdapt.getState() == BluetoothAdapter.STATE_ON)// 讀取藍牙狀態並顯示
            tbtnSwitch.setChecked(false);
        else if (btAdapt.getState() == BluetoothAdapter.STATE_OFF)
            tbtnSwitch.setChecked(true);

        // 注冊Receiver來獲取藍牙設備相關的結果
        IntentFilter intent = new IntentFilter();
        intent.addAction(BluetoothDevice.ACTION_FOUND);// 用BroadcastReceiver來取得搜索結果
        intent.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
        intent.addAction(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED);
        intent.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
        registerReceiver(searchDevices, intent);
    }

    private BroadcastReceiver searchDevices = new BroadcastReceiver() {

        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Bundle b = intent.getExtras();
            Object[] lstName = b.keySet().toArray();

            // 顯示所有收到的消息及其細節
            for (int i = 0; i < lstName.length; i++) {
                String keyName = lstName[i].toString();
                Log.e(keyName, String.valueOf(b.get(keyName)));
            }
            // 搜索設備時，取得設備的MAC地址
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent
                        .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                String str = device.getName() + "|" + device.getAddress();
                if (lstDevices.indexOf(str) == -1)// 防止重復添加
                    lstDevices.add(str); // 獲取設備名稱和mac地址
                adtDevices.notifyDataSetChanged();
            }
        }
    };

    @Override
    protected void onDestroy() {
        this.unregisterReceiver(searchDevices);
        super.onDestroy();
        android.os.Process.killProcess(android.os.Process.myPid());
    }

    class ItemClickEvent implements AdapterView.OnItemClickListener {

        @Override
        public void onItemClick(AdapterView arg0, View arg1, int arg2,
                long arg3) {
            btAdapt.cancelDiscovery();
            String str = lstDevices.get(arg2);
            String[] values = str.split("\\|");
            String address = values[1];
            Log.e("address", values[1]);
            UUID uuid = UUID.fromString(SPP_UUID);
            BluetoothDevice btDev = btAdapt.getRemoteDevice(address);
            try {
                btSocket = btDev.createRfcommSocketToServiceRecord(uuid);
                btSocket.connect();

            } catch (IOException e) {
                // TODO Auto-generated catch block

            }

        }

    }

    class ClickEvent implements View.OnClickListener {
        @Override
        public void onClick(View v) {
            if (v == btnSearch)// 搜索藍牙設備，在BroadcastReceiver顯示結果
            {
                if (btAdapt.getState() == BluetoothAdapter.STATE_OFF) {// 如果藍牙還沒開啟
                    Toast.makeText(testBlueTooth.this, "請先打開藍牙", 1000).show();
                    return;
                }
                setTitle("本機藍牙地址：" + btAdapt.getAddress());
                lstDevices.clear();
                btAdapt.startDiscovery();
            } else if (v == tbtnSwitch) {// 本機藍牙啟動/關閉
                if (tbtnSwitch.isChecked() == false)
                    btAdapt.enable();
                else if (tbtnSwitch.isChecked() == true)
                    btAdapt.disable();
            } else if (v == btnDis)// 本機可以被搜索
            {
                Intent discoverableIntent = new Intent(
                        BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
                discoverableIntent.putExtra(
                        BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
                startActivity(discoverableIntent);
            } else if (v == btnExit) {
                try {
                    if (btSocket != null)
                        btSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                testBlueTooth.this.finish();
            }
        }

    }
}