如果有人可以帮助我，我会很高兴，因为我是对象编程的新手。我的问题是：我正在编写一些带有蓝牙通信的应用程序。我在MainActivity.class中编写了所有方法并成功地在设备之间连接和传输数据。我还有一个SearchActivity.class显示列表范围内的所有设备，因此用户可以选择一个。然后设备通过 Intent 传递到MainActivity，连接开始的地方。但由于我的应用程序的性质，我必须创建单独的类，仅用于蓝牙通信，称为BluetoothService.class。我将蓝牙和其他东西的所有方法移到了BluetoothService.class。 现在我什至无法编译我的项目，因为在为 SearchActivity 创建 Intent 时出错，我也得到错误 startActivityForResult 和 onActivityResult 方法。
第一个错误是：构造函数 Intent(BluetoothService, Class) 未定义
第二个错误：方法 startActivityForResult(Intent, int) 未定义 BluetoothService 类型
public void startConnection() {
// Create an intent for SearchActivity
Intent intent = new Intent(this, SearchActivity.class);
//start SearchActivity through intent and expect for result.
//The result is based on result code, which is REQUEST_DISCOVERY
startActivityForResult(intent, REQUEST_DISCOVERY);
}
当我从 MainActivity 调用方法startConnection()时，一切正常，但现在我没有。我认为问题是，我无法从非活动类创建新活动。
下一个错误出现在 onActivityResult 方法中：*RESULT_OK 无法解析为变量*
//on ActivityResult method is called, when other activity returns result through intent!
//when user selected device in SearchActivity, result is passed through intent with //requestCode, resultCode (intent data + requestCode + resultCode)
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode != REQUEST_DISCOVERY) {
Log.d("Debug", ">>intent REQUEST_DISCOVERY failed!");
return;
}
if (resultCode != RESULT_OK) {
Log.d("Debug", ">>intent RESULT_OK failed!");
return;
}
Log.d("Debug", ">>onActivityResult!");
final BluetoothDevice device = data.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
Log.d(device.getName(), "Name of Selected Bluetoothdevice");
new Thread () {
public void run() {
//call connect function with device argument
connect(device);
};
}.start();
}
请告诉我如何解决这个问题。如果您需要更多信息或代码，请告诉我。谢谢。
public class SearchActivity extends ListActivity
{
//name of LxDevices, that will be shown on search
private String nameOfLxDevice = "DEBUG";
private Handler handler = new Handler();
/* Get Default Adapter */
private BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
/* Storage the BT devices */
private List<BluetoothDevice> devices = new ArrayList<BluetoothDevice>();
/* Discovery is Finished */
private volatile boolean discoveryFinished;
/* Start search device */
private Runnable discoveryWorker = new Runnable() {
public void run()
{
//To start discovering devices, simply call startDiscovery(). The process is asynchronous and the method will
//immediately return with a boolean indicating whether discovery has successfully started.
mBluetoothAdapter.startDiscovery();
Log.d("debug", ">>Starting Discovery");
for (;;)
{
if (discoveryFinished)
{
Log.d("debug", ">>Finished");
break;
}
try
{
Thread.sleep(100);
}
catch (InterruptedException e){}
}
}
};
/* when discovery is finished, this will be called */
//Your application must register a BroadcastReceiver for the ACTION_FOUND Intent in order to receive information about each device discovered.
//For each device, the system will broadcast the ACTION_FOUND Intent. This Intent carries the extra fields EXTRA_DEVICE and EXTRA_CLASS,
//containing a BluetoothDevice and a BluetoothClass, respectively
private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
/* get the search results */
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
//add it on List<BluetoothDevice>
devices.add(device);
//show found LxDevice on list
showDevices();
}
}
};
private BroadcastReceiver discoveryReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent)
{
/* unRegister Receiver */
Log.d("debug", ">>unregisterReceiver");
unregisterReceiver(mBroadcastReceiver);
unregisterReceiver(this);
discoveryFinished = true;
}
};
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
/* BT isEnable */
if (!mBluetoothAdapter.isEnabled())
{
Log.w("debug", ">>BT is disable!");
finish();
return;
}
/* Register Receiver*/
IntentFilter discoveryFilter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(discoveryReceiver, discoveryFilter);
IntentFilter foundFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver, foundFilter);
/* show a dialog "Scanning..." */
SamplesUtils.indeterminate(SearchActivity.this, handler, "Scanning for LX devices..", discoveryWorker, new OnDismissListener() {
public void onDismiss(DialogInterface dialog)
{
for (; mBluetoothAdapter.isDiscovering();) {
// Discovery is resource intensive. Make sure it isn't going on when you attempt to connect and pass your message.
mBluetoothAdapter.cancelDiscovery();
}
discoveryFinished = true;
}
}, true);
}
/* Show devices list */
private void showDevices()
{
//Create a list of strings
List<String> list = new ArrayList<String>();
for (int i = 0, size = devices.size(); i < size; ++i) {
StringBuilder b = new StringBuilder();
BluetoothDevice d = devices.get(i);
b.append(d.getName());
b.append('\n');
b.append(d.getAddress());
String s = b.toString();
list.add(s);
}
Log.d("debug", ">>showDevices");
final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);
handler.post(new Runnable() {
public void run()
{
setListAdapter(adapter);
}
});
}
/* Select device */
protected void onListItemClick(ListView l, View v, int position, long id) {
Log.d("debug", ">>Click device");
Intent result = new Intent();
result.putExtra(BluetoothDevice.EXTRA_DEVICE, devices.get(position));
setResult(RESULT_OK, result);
finish();
}
}
在 MainActivity 我正在做：
// Initialize the BluetoothChatService to perform bluetooth connections
mBluetoothService = new BluetoothService(this);
BluetoothService 中的构造函数是：
public BluetoothService(Context context) {
}
连接方法：
protected void connect(BluetoothDevice device) {
try {
//Create a Socket connection: need the server's UUID number of registered
BluetoothSocket socket = null;
socket = device.createRfcommSocketToServiceRecord(MY_UUID);
socket.connect();
//Create temporary input and output stream
InputStreamtmpIn=socket.getInputStream();
OutputStream tmpOut = socket.getOutputStream();
//for use purposes
mmSocket = socket;
mmOutStream = tmpOut;
mmInStream = tmpIn;
tmpOut.write("Device connected..".getBytes());
//start Thread for receiving data over bluetooth
//dataReceiveThread.start();
} catch (IOException e) {
Log.e("Colibri2BB BT", "", e);
}
}