Question

这段 安卓软件中的代码中如何判断 手机是否连接到 蓝牙设备

public class BluetoothConnection
{
static BluetoothSocket btSock = null;

public static void closeConnection()
{
if (btSock == null)
return;
try
{
btSock.getInputStream().close();
btSock.getOutputStream().close();
btSock.close();
btSock = null;
return;
}
catch (IOException localIOException)
{
}
}

public static int doTelescopeCommand(byte[] paramArrayOfByte1, int paramInt1, byte[] paramArrayOfByte2, int paramInt2, byte paramByte, int paramInt3)
{
int i = Telescope.TEL_SERIAL_READ_ERROR;
byte[] arrayOfByte = new byte[256];
try
{
OutputStream localOutputStream = btSock.getOutputStream();
InputStream localInputStream = btSock.getInputStream();
while (true)
{
i = Telescope.TEL_SERIAL_WRITE_ERROR;
if ((paramInt1 > 0) && (paramArrayOfByte1 != null))
{
localOutputStream.write(paramArrayOfByte1);
localOutputStream.flush();
}
if (paramInt2 < 1)
return Telescope.TEL_NO_ERROR;
do
{
int k = localInputStream.available();
if (k >= 1);
localInputStream.read(arrayOfByte, 0, Math.min(k, 256));
continue;
long l = System.currentTimeMillis() + paramInt3;
i = Telescope.TEL_SERIAL_READ_ERROR;
int j = 0;
if (System.currentTimeMillis() >= l)
i = Telescope.TEL_TIMEOUT_ERROR;
while (true)。。。。。 还有不少代码，自己只能看懂个大概

Answer 1

安卓蓝牙中。要连接其他设备要调用connect()函数。。此函数你可以去看一下，官方说的是：若连接成功，就不会产生异常。不成功，就会产生异常。。。所以看看程序会运行异常不。运行了，说明没有连接成功。没运行，则连接成功了。
try {
// 连接
connect(device);
} catch (IOException e) {
Toast.makeText(MainActivity.this, "没有成功连接设备", //1
Toast.LENGTH_SHORT).show();
}

若成功了，不会运行1，不成功，就会产生异常。运行异常中的程序，也就是代码1.

Answer 2

Android对于蓝牙开发从2.0版本的sdk才开始支持，而且模拟器不支持，测试至少需要两部手机，所以制约了很多技术人员的开发。
1. 首先，要操作蓝牙，先要在AndroidManifest.xml里加入权限
// 管理蓝牙设备的权限
<uses-permissionandroid:name="android.permission.BLUETOOTH_ADMIN" />
// 使用蓝牙设备的权限
<uses-permissionandroid:name="android.permission.BLUETOOTH" />
2.打开蓝牙
获得蓝牙适配器（android.bluetooth.BluetoothAdapter），检查该设备是否支持蓝牙，如果支持，就打开蓝牙。
[java]
// 检查设备是否支持蓝牙
adapter = BluetoothAdapter.getDefaultAdapter();
if (adapter == null)
{
// 设备不支持蓝牙
}
// 打开蓝牙
if (!adapter.isEnabled())
{
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
// 设置蓝牙可见性，最多300秒
intent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
context.startActivity(intent);
}
// 检查设备是否支持蓝牙
adapter = BluetoothAdapter.getDefaultAdapter();
if (adapter == null)
{
// 设备不支持蓝牙
}
// 打开蓝牙
if (!adapter.isEnabled())
{
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
// 设置蓝牙可见性，最多300秒
intent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
context.startActivity(intent);
}
3.获取已配对的蓝牙设备（android.bluetooth.BluetoothDevice）
首次连接某蓝牙设备需要先配对，一旦配对成功，该设备的信息会被保存，以后连接时无需再配对，所以已配对的设备不一定是能连接的。
[java]
BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
Set<BluetoothDevice> devices = adapter.getBondedDevices();
for(int i=0; i<devices.size(); i++)
{
BluetoothDevice device = (BluetoothDevice) devices.iterator().next();
System.out.println(device.getName());
}
BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
Set<BluetoothDevice> devices = adapter.getBondedDevices();
for(int i=0; i<devices.size(); i++)
{
BluetoothDevice device = (BluetoothDevice) devices.iterator().next();
System.out.println(device.getName());
}
4.搜索周围的蓝牙设备
适配器搜索蓝牙设备后将结果以广播形式传出去，所以需要自定义一个继承广播的类，在onReceive方法中获得并处理蓝牙设备的搜索结果。
[java]
// 设置广播信息过滤
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(BluetoothDevice.ACTION_FOUND);
intentFilter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
intentFilter.addAction(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED);
intentFilter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
// 注册广播接收器，接收并处理搜索结果
context.registerReceiver(receiver, intentFilter);
// 寻找蓝牙设备，android会将查找到的设备以广播形式发出去
adapter.startDiscovery();
// 设置广播信息过滤
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(BluetoothDevice.ACTION_FOUND);
intentFilter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
intentFilter.addAction(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED);
intentFilter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
// 注册广播接收器，接收并处理搜索结果
context.registerReceiver(receiver, intentFilter);
// 寻找蓝牙设备，android会将查找到的设备以广播形式发出去
adapter.startDiscovery(); 自定义广播类
[java]
private BroadcastReceiver receiver = 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);
System.out.println(device.getName());
}
}
}
private BroadcastReceiver receiver = 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);
System.out.println(device.getName());
}
}
}
5.蓝牙设备的配对和状态监视
[java]
private BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// 获取查找到的蓝牙设备
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
System.out.println(device.getName());
// 如果查找到的设备符合要连接的设备，处理
if (device.getName().equalsIgnoreCase(name)) {
// 搜索蓝牙设备的过程占用资源比较多，一旦找到需要连接的设备后需要及时关闭搜索
adapter.cancelDiscovery();
// 获取蓝牙设备的连接状态
connectState = device.getBondState();
switch (connectState) {
// 未配对
case BluetoothDevice.BOND_NONE:
// 配对
try {
Method createBondMethod = BluetoothDevice.class.getMethod("createBond");
createBondMethod.invoke(device);
} catch (Exception e) {
e.printStackTrace();
}
break;
// 已配对
case BluetoothDevice.BOND_BONDED:
try {
// 连接
connect(device);
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}
} else if(BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) {
// 状态改变的广播
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (device.getName().equalsIgnoreCase(name)) {
connectState = device.getBondState();
switch (connectState) {
case BluetoothDevice.BOND_NONE:
break;
case BluetoothDevice.BOND_BONDING:
break;
case BluetoothDevice.BOND_BONDED:
try {
// 连接
connect(device);
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}
}
}
}
private BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// 获取查找到的蓝牙设备
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
System.out.println(device.getName());
// 如果查找到的设备符合要连接的设备，处理
if (device.getName().equalsIgnoreCase(name)) {
// 搜索蓝牙设备的过程占用资源比较多，一旦找到需要连接的设备后需要及时关闭搜索
adapter.cancelDiscovery();
// 获取蓝牙设备的连接状态
connectState = device.getBondState();
switch (connectState) {
// 未配对
case BluetoothDevice.BOND_NONE:
// 配对
try {
Method createBondMethod = BluetoothDevice.class.getMethod("createBond");
createBondMethod.invoke(device);
} catch (Exception e) {
e.printStackTrace();
}
break;
// 已配对
case BluetoothDevice.BOND_BONDED:
try {
// 连接
connect(device);
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}
} else if(BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) {
// 状态改变的广播
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (device.getName().equalsIgnoreCase(name)) {
connectState = device.getBondState();
switch (connectState) {
case BluetoothDevice.BOND_NONE:
break;
case BluetoothDevice.BOND_BONDING:
break;
case BluetoothDevice.BOND_BONDED:
try {
// 连接
connect(device);
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}
}
}
} 6.蓝牙设备的连接
[java]
private void connect(BluetoothDevice device) throws IOException {
// 固定的UUID
final String SPP_UUID = "00001101-0000-1000-8000-00805F9B34FB";
UUID uuid = UUID.fromString(SPP_UUID);
BluetoothSocket socket = device.createRfcommSocketToServiceRecord(uuid);
socket.connect();
}
private void connect(BluetoothDevice device) throws IOException {
// 固定的UUID
final String SPP_UUID = "00001101-0000-1000-8000-00805F9B34FB";
UUID uuid = UUID.fromString(SPP_UUID);
BluetoothSocket socket = device.createRfcommSocketToServiceRecord(uuid);
socket.connect();
}