通过多种活动保持android蓝牙连接
我正在构建一个Android应用程序，通过蓝牙与Arduino板进行通信，我在一个名为BlueComms的类中拥有蓝牙代码。要连接到设备，我使用以下方法：通过多种活动保持android蓝牙连接,android,android-intent,android-activity,bluetooth,onpause,Android,Android Intent,Android Activity,Bluetooth,Onpause,我正在构建一个Android应用程序，通过蓝牙与Arduino板进行通信，我在一个名为BlueComms的类中拥有蓝牙代码。要连接到设备，我使用以下方法： public boolean connectDevice() { CheckBt(); BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address); Log.d(TAG, "Connecting to ... " + device);
public boolean connectDevice() {
CheckBt();
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
Log.d(TAG, "Connecting to ... " + device);
mBluetoothAdapter.cancelDiscovery();
try {
btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
btSocket.connect();
outStream = btSocket.getOutputStream();
Log.d(TAG, "Connection made.");
return true;
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
Log.d(TAG, "Unable to end the connection");
return false;
}
Log.d(TAG, "Socket creation failed");
}
return false;
}
private void CheckBt() {
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (!mBluetoothAdapter.isEnabled()) {
System.out.println("Bt dsbld");
}
if (mBluetoothAdapter == null) {
System.out.println("Bt null");
}
}
D/dalvikvm(21623): GC_CONCURRENT freed 103K, 10% free 2776K/3056K, paused 5ms+2ms, total 35ms
public void sendData(String data, int recvAct) {
try {
outStream = btSocket.getOutputStream();
} catch (IOException e) {
Log.d(TAG, "Bug BEFORE Sending stuff", e);
}
String message = data;
byte[] msgBuffer = message.getBytes();
try {
outStream.write(msgBuffer);
} catch (IOException e) {
Log.d(TAG, "Bug while sending stuff", e);
}
}
Intent myIntent = new Intent(v.getContext(), Timelapse.class);
startActivityForResult(myIntent, 0);
Rozz您将BlueComms类的实例存储在哪里？如果您将其放在第一个活动中，那么当您离开该活动并移动到下一个活动时，该类实例将被销毁（NB活动也会在屏幕旋转时被销毁） 因此，您需要找到一种方法，使BlueComms类的实例在您需要的时间内保持活动状态。您可以通过公共属性在活动之间传递它，并在旋转期间将其存储在OnRetainonConfiguration Instance（）中 一个更简单的技巧是创建一个扩展
应用程序的类import android.app.Application;
public class cBaseApplication extends Application {
public BlueComms myBlueComms;
@Override
public void onCreate()
{
super.onCreate();
myBlueComms = new BlueComms();
}
}
<application
android:name="your.app.namespace.cBaseApplication"
android:icon="@drawable/icon"
android:label="@string/app_name" >
当您选择要连接的设备时，以及当您选择要连接的设备时，单击设备列表项以请求连接到该设备，请使用异步任务 并将connect方法放在AsyncTask中，如下所示：-
AsyncTask.execute(new Runnable() {
@Override
public void run() {
try {
bluetoothSocket = Globals.bluetoothDevice.createRfcommSocketToServiceRecord(Globals.DEFAULT_SPP_UUID);
bluetoothSocket.connect();
// After successful connect you can open InputStream
} catch (IOException e) {
e.printStackTrace();
}
**Here is the full code for the same problem that i have cracked :-**
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
lablelexconnected.setText("Connecting ...");
bdDevice = arrayListBluetoothDevices.get(position);
//bdClass = arrayListBluetoothDevices.get(position)
// Toast.makeText(getApplicationContext()," " + bdDevice.getAddress(),Toast.LENGTH_SHORT).show();
Log.i("Log", "The dvice : " + bdDevice.toString());
bdDevice = bluetoothAdapter.getRemoteDevice(bdDevice.getAddress());
Globals.bluetoothDevice = bluetoothAdapter.getRemoteDevice(bdDevice.getAddress());
System.out.println("Device in GPS Settings : " + bdDevice);
// startService(new Intent(getApplicationContext(),MyService.class));
/* Intent i = new Intent(GpsSettings.this, MyService.class);
startService(i);*/
// finish();
// connectDevice();
AsyncTask.execute(new Runnable() {
@Override
public void run() {
try {
bluetoothSocket = Globals.bluetoothDevice.createRfcommSocketToServiceRecord(Globals.DEFAULT_SPP_UUID);
bluetoothSocket.connect();
// After successful connect you can open InputStream
InputStream in = null;
in = bluetoothSocket.getInputStream();
InputStreamReader isr = new InputStreamReader(in);
br = new BufferedReader(isr);
while (found == 0) {
String nmeaMessage = br.readLine();
Log.d("NMEA", nmeaMessage);
// parse NMEA messages
sentence = nmeaMessage;
System.out.println("Sentence : " + sentence);
if (sentence.startsWith("$GPRMC")) {
String[] strValues = sentence.split(",");
System.out.println("StrValues : " + strValues[3] + " " + strValues[5] + " " + strValues[8]);
if (strValues[3].equals("") && strValues[5].equals("") && strValues[8].equals("")) {
Toast.makeText(getApplicationContext(), "Location Not Found !!! ", Toast.LENGTH_SHORT).show();
} else {
latitude = Double.parseDouble(strValues[3]);
if (strValues[4].charAt(0) == 'S') {
latitude = -latitude;
}
longitude = Double.parseDouble(strValues[5]);
if (strValues[6].charAt(0) == 'W') {
longitude = -longitude;
}
course = Double.parseDouble(strValues[8]);
// Toast.makeText(getApplicationContext(), "latitude=" + latitude + " ; longitude=" + longitude + " ; course = " + course, Toast.LENGTH_SHORT).show();
System.out.println("latitude=" + latitude + " ; longitude=" + longitude + " ; course = " + course);
// found = 1;
NMEAToDecimalConverter(latitude, longitude);
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
});
AsyncTask.execute（新的Runnable（）{
@凌驾
公开募捐{
试一试{
bluetoothSocket=Globals.bluetoothDevice.createRfcommSocketToServiceRecord（Globals.DEFAULT\u SPP\u UUID）；
bluetoothSocket.connect（）；
//成功连接后，可以打开InputStream
}捕获（IOE异常）{
e、 printStackTrace（）；
}
**下面是我破解的同一个问题的完整代码：-**
setOnItemClickListener（新的AdapterView.OnItemClickListener（）{
@凌驾
public void onItemClick（AdapterView父对象、视图、整型位置、长id）{
lableExconnected.setText（“连接…”）；
bdDevice=arrayListBluetoothDevices.get（位置）；
//bdClass=arrayListBluetoothDevices.get（位置）
//Toast.makeText（getApplicationContext（），“”+bdDevice.getAddress（），Toast.LENGTH\u SHORT）.show（）；
Log.i（“Log”，“dvice:+bdDevice.toString（））；
bdDevice=bluetoothAdapter.getRemoteDevice（bdDevice.getAddress（））；
Globals.bluetoothDevice=bluetoothAdapter.getRemoteDevice（bdDevice.getAddress（））；
System.out.println（“GPS设置中的设备：“+bdDevice”）；
//startService（新的意图（getApplicationContext（），MyService.class））；
/*意图i=新意图（GpsSettings.this、MyService.class）；
startService（一）*/
//完成（）；
//连接设备（）；
AsyncTask.execute（新的Runnable（）{
@凌驾
公开募捐{
试一试{
bluetoothSocket=Globals.bluetoothDevice.createRfcommSocketToServiceRecord（Globals.DEFAULT\u SPP\u UUID）；
bluetoothSocket.connect（）；
//成功连接后，可以打开InputStream
InputStream in=null；
in=bluetoothSocket.getInputStream（）；
InputStreamReader isr=新的InputStreamReader（in）；
br=新的缓冲读取器（isr）；
while（找到==0）{
字符串nmeaMessage=br.readLine（）；
Log.d（“NMEA”，NMAMessage）；
//解析NMEA消息
句子=N留言；
System.out.println（“句子：”+句子）；
如果（句子.startsWith（“$GPRMC”））{
String[]strValues=句子.split（“，”）；
System.out.println（“StrValues:+StrValues[3]+”“+StrValues[5]+”“+StrValues[8]）；
if（strValues[3]。等于（“”&&strValues[5]。等于（“”&&strValues[8]。等于（“”）{
Toast.makeText（getApplicationContext（），“找不到位置！！！”，Toast.LENGTH\u SHORT.show（）；
}否则{
纬度=Double.parseDouble（标准值[3]）；
if（strValues[4]。字符（0）='S'）{
纬度=-纬度；
}
经度=Double.parseDouble（标准值[5]）；
if（标准值[6]。字符（0）==“W”）{
经度=-经度；
}
course=Double.parseDouble（标准值[8]）；
//Toast.makeText（getApplicationContext（），“latitude=“+latitude+”；longitude=“+longitude+”；course=“+course，Toast.LENGTH\u SHORT）.show（）；
s
AsyncTask.execute(new Runnable() {
@Override
public void run() {
try {
bluetoothSocket = Globals.bluetoothDevice.createRfcommSocketToServiceRecord(Globals.DEFAULT_SPP_UUID);
bluetoothSocket.connect();
// After successful connect you can open InputStream
} catch (IOException e) {
e.printStackTrace();
}
**Here is the full code for the same problem that i have cracked :-**
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
lablelexconnected.setText("Connecting ...");
bdDevice = arrayListBluetoothDevices.get(position);
//bdClass = arrayListBluetoothDevices.get(position)
// Toast.makeText(getApplicationContext()," " + bdDevice.getAddress(),Toast.LENGTH_SHORT).show();
Log.i("Log", "The dvice : " + bdDevice.toString());
bdDevice = bluetoothAdapter.getRemoteDevice(bdDevice.getAddress());
Globals.bluetoothDevice = bluetoothAdapter.getRemoteDevice(bdDevice.getAddress());
System.out.println("Device in GPS Settings : " + bdDevice);
// startService(new Intent(getApplicationContext(),MyService.class));
/* Intent i = new Intent(GpsSettings.this, MyService.class);
startService(i);*/
// finish();
// connectDevice();
AsyncTask.execute(new Runnable() {
@Override
public void run() {
try {
bluetoothSocket = Globals.bluetoothDevice.createRfcommSocketToServiceRecord(Globals.DEFAULT_SPP_UUID);
bluetoothSocket.connect();
// After successful connect you can open InputStream
InputStream in = null;
in = bluetoothSocket.getInputStream();
InputStreamReader isr = new InputStreamReader(in);
br = new BufferedReader(isr);
while (found == 0) {
String nmeaMessage = br.readLine();
Log.d("NMEA", nmeaMessage);
// parse NMEA messages
sentence = nmeaMessage;
System.out.println("Sentence : " + sentence);
if (sentence.startsWith("$GPRMC")) {
String[] strValues = sentence.split(",");
System.out.println("StrValues : " + strValues[3] + " " + strValues[5] + " " + strValues[8]);
if (strValues[3].equals("") && strValues[5].equals("") && strValues[8].equals("")) {
Toast.makeText(getApplicationContext(), "Location Not Found !!! ", Toast.LENGTH_SHORT).show();
} else {
latitude = Double.parseDouble(strValues[3]);
if (strValues[4].charAt(0) == 'S') {
latitude = -latitude;
}
longitude = Double.parseDouble(strValues[5]);
if (strValues[6].charAt(0) == 'W') {
longitude = -longitude;
}
course = Double.parseDouble(strValues[8]);
// Toast.makeText(getApplicationContext(), "latitude=" + latitude + " ; longitude=" + longitude + " ; course = " + course, Toast.LENGTH_SHORT).show();
System.out.println("latitude=" + latitude + " ; longitude=" + longitude + " ; course = " + course);
// found = 1;
NMEAToDecimalConverter(latitude, longitude);
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
});
Class MyBTConnection{
private static MyBTConnection connectionObj;
private Handler mHandler;
public MyBTConnection() { //constructor }
public static MyBTConnection getInstance() {
if(connectionObj == null) {
connectionObj = new MyBTConnection();
}
return connectionObj;
}
}
public void setHandler(Handler handler) {
mHandler = handler;
}
..... Code for Bluetooth Connection ....
to send message :
mHandler.obtainMessage(what).sendToTarget();
}
// in first activity
class MainActivity extends Activity {
private MyBTConnection connectionObj;
public onCreate(....) {
/*
* Since this is first call for getInstance. A new object
* of MyBTConnection will be created and a connection to
* remote bluetooth device will be established.
*/
connectionObj = MyBTConnection.getInstance();
connectionObj.setHandler(mHandler);
}
private Handler mHandler = new Handler(){
public void onReceive(...) {
/// handle received messages here
}
};
}
// in second activity
class SecondActivity extends Activity {
private MyBTConnection connectionObj;
public onCreate(....) {
/*
* Since this is second call for getInstance.
* Object for MyBTConnection was already created in previous
* activity. So getInstance will return that previously
* created object and in that object, connection to remote
* bluetooth device is already established so you can
* continue your work here.
*/
connectionObj = MyBTConnection.getInstance();
connectionObj.setHandler(mHandler);
}
private Handler mHandler = new Handler(){
public void onReceive(...) {
/// handle received messages here
}
};
}