I will be very happy if someone can help me, because I'm new at object programming. My problem is: I'm writting some app with bluetooth communication. I wrote all methods and successfully connect and transfer data between devices in MainActivity.class . I have also one SearchActivity.class which shows all devices in range on List, so user can pick one. Device is then passed through Intent to MainActivity , where connection starts. But because of nature of my app I must created separate class, just for Bluetooth communication called BluetoothService.class . I moved all methods for Bluetooth and other stuff to BluetoothService.class. Now I even can't compile my project, because I get error at creating Intent for SearchActivity, I also get error startActivityForResult and onActivityResult methods.
First error is: The constructor Intent(BluetoothService, Class) is undefined
Second error: The method startActivityForResult(Intent, int) is undefined for the type BluetoothService
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);
}
When I was calling method startConnection() from MainActivity everything worked, but now I it doesn't. I think the problem is, that I can't create new Activity from non-activity class.
Next error is in onActivityResult method: *RESULT_OK cannot be resolved to a variable*
//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();
}
Please, tell me how can I solve this. If you need more info or code tell me. Thanks.
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();
}
}
In MainActivity I am doing:
// Initialize the BluetoothChatService to perform bluetooth connections
mBluetoothService = new BluetoothService(this);
Constructor in BluetoothService is:
public BluetoothService(Context context) {
}
connect method:
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);
}
}
Your BluettoothService
class is not a context and to initialise an Intent you need a context.So try creating your class like this:
public class BluettoothService{
Activity activity;
BluettoothService(Activity activity){
this.activity=activity;
}
public void startConnection() {
// Create an intent for SearchActivity
Intent intent = new Intent(activity, SearchActivity.class);
//start SearchActivity through intent and expect for result.
//The result is based on result code, which is REQUEST_DISCOVERY
activity.startActivityForResult(intent, REQUEST_DISCOVERY);
}
}
And you can create the BluettoothService
class this way from any activity:
BluettoothService bluetooth=new BluettoothService(this);
Edit:
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode != REQUEST_DISCOVERY) {
Log.d("Debug", ">>intent REQUEST_DISCOVERY failed!");
return;
}
if (resultCode != Activity.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();
}
您不能使用this
服务来启动ActivityForResult
You should to specify the @override
for the onActivityResult()
.
Your code should to be put into a class who extends 'activity' (android.app.Activity). It's for that you have also this :
Next error is in onActivityResult method: *RESULT_OK cannot be resolved to a variable*
This cannot be resolved because your class don't extends 'Activity'
//create this class that hold application context.
public class Application_Manager extends Application {
private static Context context;
public void onCreate() {
super.onCreate();
Application_Manager.context = getApplicationContext();
}
public static Context getAppContext() {
return Application_Manager.context;
}
}
//use this class getAppcontext() to get context in non-activity class.
public class BluettoothService{
static Context context=Application_Manager.getAppContext();
public void startConnection() {
Intent intent = new Intent(context, SearchActivity.class);
context.startActivityForResult(intent, REQUEST_DISCOVERY);//change edited
}
}
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