我尝试将数据从我的应用程序发送到我的Arduino板以制作LED灯。
问题是，如果我从我的主要活动发送它有效，但如果我从第二个活动（HolopickerColor）发送它，它不起作用，我不会得到任何错误。
谢谢你的导师。
MainActivity：
public class MainActivity extends AppCompatActivity{
private Button mPairedBtn;
Button on, find;
public BluetoothAdapter BA;
private ProgressDialog mProgressDlg;
// public ConnectedThread mConnectedThread;
private ArrayList<BluetoothDevice> mDeviceList = new ArrayList<BluetoothDevice>();
private DrawerLayout mDrawerLayout;
private BluetoothSocket btSocket = null;
private OutputStream outStream = null;
Button btnOn, btnOff;
// SPP UUID service
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// MAC-address of Bluetooth module (you must edit this line)
private static String address ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
on = (Button) findViewById(R.id.btn_enable);
find = (Button) findViewById(R.id.btn_scan);
mPairedBtn = (Button) findViewById(R.id.btn_view_paired);
BA = BluetoothAdapter.getDefaultAdapter();
mProgressDlg = new ProgressDialog(this);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
ActionBar actionBar = getSupportActionBar();
actionBar.setHomeAsUpIndicator(R.drawable.ic_menu);
actionBar.setDisplayHomeAsUpEnabled(true);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
NavigationView navigationView = (NavigationView) findViewById(R.id.navigation_view);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
menuItem.setChecked(true);
mDrawerLayout.closeDrawers();
Toast.makeText(MainActivity.this, menuItem.getTitle(), Toast.LENGTH_LONG).show();
switch (menuItem.getItemId()) {
case R.id.nav_item_colorlight:
Intent color = new Intent(MainActivity.this, HolopickerColor.class);
// color.putExtra("color", ConnectedThread.getInstance());
startActivity(color);
break;
case R.id.nav_item_effectlight:
Intent light = new Intent(MainActivity.this, LightEffect.class);
startActivity(light);
break;
case R.id.nav_item_music:
Intent music = new Intent(MainActivity.this, Music.class);
startActivity(music);
break;
case R.id.nav_item_about:
Intent about = new Intent(MainActivity.this, About.class);
startActivity(about);
break;
}
return true;
}
});
mProgressDlg.setMessage("Scanning...");
mProgressDlg.setCancelable(false);
mProgressDlg.setButton(DialogInterface.BUTTON_NEGATIVE, "Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
BA.cancelDiscovery();
}
});
if (BA == null) {
showUnsupported();
} else {
mPairedBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Set<BluetoothDevice> pairedDevices = BA.getBondedDevices();
if (pairedDevices == null || pairedDevices.size() == 0) {
showToast("No Paired Devices Found");
} else {
ArrayList<BluetoothDevice> list = new ArrayList<BluetoothDevice>();
list.addAll(pairedDevices);
Intent intent = new Intent(MainActivity.this, DeviceListActivity.class);
intent.putParcelableArrayListExtra("device.list", list);
startActivity(intent);
}
}
});
find.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
BA.startDiscovery();
}
});
on.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (BA.isEnabled()) {
BA.disable();
showDisabled();
try
{
btSocket.close();
} catch (IOException e2)
{
//insert code to deal with this
}
} else {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, 1000);
}
}
});
if (BA.isEnabled()) {
showEnabled();
} else {
showDisabled();
}
}
IntentFilter filter = new IntentFilter();
filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mReceiver, filter);
btnOn = (Button) findViewById(R.id.btnOn);
btnOff = (Button) findViewById(R.id.btnOff);
// Set up onClick listeners for buttons to send 1 or 0 to turn on/off LED
btnOff.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
/* r = 255;
g = 15;
b = 50;
mConnectedThread.write("r"+Integer.toString(r)+"\n"); // Send "0" via Bluetooth
mConnectedThread.write("g"+Integer.toString(g)+"\n");
mConnectedThread.write("b"+Integer.toString(b)+"\n");*/
ConnectedThread.getInstance().write("1");
Toast.makeText(getBaseContext(), "Turn off LED", Toast.LENGTH_SHORT).show();
}
});
btnOn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
//cathode nen 1 la off, o la on
ConnectedThread.getInstance().write("0"); // Send "1" via Bluetooth //gui nhan ne
Toast.makeText(getBaseContext(), "Turn on LED", Toast.LENGTH_SHORT).show();
}
});
//Get MAC address from DeviceListActivity via intent
// Intent intent = getIntent();
//Get the MAC address from the DeviceListActivty via EXTRA
//address = intent.getStringExtra(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
// MAC-address of Bluetooth module (you must edit this line)
address = "30:14:10:09:07:86";
//create device and set the MAC address
BluetoothDevice device = BA.getRemoteDevice(address);
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e) {
Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_LONG).show();
}
// Establish the Bluetooth socket connection.
try
{
btSocket.connect();
} catch (IOException e) {
try
{
btSocket.close();
} catch (IOException e2)
{
//insert code to deal with this
}
}
ConnectedThread.createInstance(btSocket);
ConnectedThread.getInstance().start();
//I send a character when resuming.beginning transmission to check device is connected
//If it is not an exception will be thrown in the write method and finish() will be called
}
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
return device.createRfcommSocketToServiceRecord(MY_UUID);
//creates secure outgoing connecetion with BT device using UUID
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
switch (id) {
case android.R.id.home:
mDrawerLayout.openDrawer(GravityCompat.START);
return true;
}
return super.onOptionsItemSelected(item);
}
public void onPause() {
if (BA != null) {
if (BA.isDiscovering()) {
BA.cancelDiscovery();
}
}
try
{
//Don't leave Bluetooth sockets open when leaving activity
btSocket.close();
} catch (IOException e2) {
//insert code to deal with this
}
super.onPause();
}
@Override
public void onDestroy() {
unregisterReceiver(mReceiver);
super.onDestroy();
}
private void showEnabled() {
Toast.makeText(getApplicationContext(), "on", Toast.LENGTH_LONG).show();
on.setText("Disable");
on.setEnabled(true);
mPairedBtn.setEnabled(true);
find.setEnabled(true);
}
private void showDisabled() {
Toast.makeText(getApplicationContext(), "off", Toast.LENGTH_LONG).show();
on.setText("Enable");
on.setEnabled(true);
mPairedBtn.setEnabled(false);
find.setEnabled(false);
}
private void showUnsupported() {
Toast.makeText(getApplicationContext(), "Bluetooth is unsupported by this device", Toast.LENGTH_LONG).show();
on.setText("Enable");
on.setEnabled(false);
mPairedBtn.setEnabled(false);
find.setEnabled(false);
}
private void showToast(String message) {
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
final int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR);
if (state == BluetoothAdapter.STATE_ON) {
showToast("Enabled");
showEnabled();
}
} else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
mDeviceList = new ArrayList<BluetoothDevice>();
mProgressDlg.show();
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
mProgressDlg.dismiss();
Intent newIntent = new Intent(MainActivity.this, DeviceListActivity.class);
newIntent.putParcelableArrayListExtra("device.list", mDeviceList);
startActivity(newIntent);
} else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = (BluetoothDevice) intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
mDeviceList.add(device);
showToast("Found device " + device.getName());
}
}
};
第二项活动：
public class HolopickerColor extends AppCompatActivity implements ColorPicker.OnColorChangedListener {
private TextView text;
com.larswerkman.holocolorpicker.ColorPicker picker;
SVBar svBar ;
Button test;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_holopicker_color);
picker = (ColorPicker) findViewById(R.id.picker);
svBar = (SVBar) findViewById(R.id.svbar);
text = (TextView) findViewById(R.id.color1);
picker.addSVBar(svBar);
picker.getColor();
picker.setOnColorChangedListener(this);
picker.setShowOldCenterColor(false);// Tat mau cu
test = (Button)findViewById(R.id.test);
test.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
ConnectedThread.getInstance().write("r255\n");
Toast.makeText(getBaseContext(),"yes",Toast.LENGTH_LONG).show();
}
});
//ConnectedThread.getInstance().start();
}
public void onColorChanged(int color) {
// TODO Auto-generated method stub
text.setTextColor(color);//hien mau len chu
if (ConnectedThread.getInstance() != null) {
int r = (color >> 16) & 0xFF;//xuat kieu mau ra thanh chu
int g = (color >> 8) & 0xFF;
int b = (color >> 0) & 0xFF;
// mTcpClient.sendMessage(Integer.toHexString(picker.getColor()));
ConnectedThread.getInstance().write("r255");//gui ko nhan ne
以下是ConnectedThread：
class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final OutputStream mmOutStream; // cai nay e can implement Serializable nua
private static ConnectedThread instance = null;
private ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmOutStream = tmpOut;
}
public static void createInstance(BluetoothSocket socket) {
if (instance == null) {
instance = new ConnectedThread(socket);
}
}
public static ConnectedThread getInstance() {
return instance;
}
//write method
public void write(String input) {
byte[] msgBuffer = input.getBytes(); //converts entered String into bytes
try {
mmOutStream.write(msgBuffer); //write bytes over BT connection via outstream
} catch (IOException e) {
cancel();
}
}
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
答案 0 :(得分：0)
问题是您使用ConnectedThread创建BluetoothSocket单例实例，然后在活动的onPause方法中关闭同一个套接字。所以基本上，在调用onPause之后，ConnectedThread实例不再发送任何内容。取而代之的是，您应该ConnectedThread管理套接字，即保留对它的引用，然后在不再需要它或检测到问题时将其关闭。
顺便说一下，每次在套接字关闭后在write上调用ConnectedThread时，都会调用cancel方法。如果您没有在此方法中静默异常，您将能够轻松地检测到问题。这就是为什么你永远不应该有一个空catch块。