我的DeviceList.java代码如下： -
import com.technomentis.led.R;
public class DeviceList extends ActionBarActivity
{
//widgets
Button btnPaired;
ListView devicelist;
//Bluetooth
private BluetoothAdapter myBluetooth = null;
private Set<BluetoothDevice> pairedDevices;
public static String EXTRA_ADDRESS = "device_address";
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_device_list);
//Calling widgets
btnPaired = (Button)findViewById(R.id.btnOn);
devicelist = (ListView)findViewById(R.id.listView);
//if the device has bluetooth
myBluetooth = BluetoothAdapter.getDefaultAdapter();
if(myBluetooth == null)
{
//Show a mensag. that the device has no bluetooth adapter
Toast.makeText(getApplicationContext(), "Bluetooth Device Not Available", Toast.LENGTH_LONG).show();
//finish apk
finish();
}
else if(!myBluetooth.isEnabled())
{
//Ask to the user turn the bluetooth on
Intent turnBTon = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnBTon,1);
}
btnPaired.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
pairedDevicesList();
}
});
}
private void pairedDevicesList()
{
pairedDevices = myBluetooth.getBondedDevices();
ArrayList list = new ArrayList();
if (pairedDevices.size()>0)
{
for(BluetoothDevice bt : pairedDevices)
{
list.add(bt.getName() + "\n" + bt.getAddress()); //Get the device's name and the address
}
}
else
{
Toast.makeText(getApplicationContext(), "No Paired Bluetooth Devices Found.", Toast.LENGTH_LONG).show();
}
final ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1, list);
devicelist.setAdapter(adapter);
devicelist.setOnItemClickListener(myListClickListener); //Method called when the device from the list is clicked
}
private AdapterView.OnItemClickListener myListClickListener = new AdapterView.OnItemClickListener()
{
public void onItemClick (AdapterView<?> av, View v, int arg2, long arg3)
{
// Get the device MAC address, the last 17 chars in the View
String info = ((TextView) v).getText().toString();
String address = info.substring(info.length() - 17);
// Make an intent to start next activity.
Intent i = new Intent(DeviceList.this, ledControl.class);
//Change the activity.
i.putExtra(EXTRA_ADDRESS, address); //this will be received at ledControl (class) Activity
startActivity(i);
}
};
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_device_list, menu);
return true;
}
@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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
我的ledcontrol.java如下
package com.technomentis.led;
public class ledControl extends ActionBarActivity {
Button btnOn, btnOff, btnDis;
SeekBar brightness;
TextView lumn;
String address = null;
private ProgressDialog progress;
BluetoothAdapter myBluetooth = null;
BluetoothSocket btSocket = null;
private boolean isBtConnected = false;
//SPP UUID. Look for it
static final UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Intent newint = getIntent();
address = newint.getStringExtra(DeviceList.EXTRA_ADDRESS); //receive the address of the bluetooth device
//view of the ledControl
setContentView(R.layout.activity_led_control);
//call the widgtes
btnOn = (Button)findViewById(R.id.button2);
btnOff = (Button)findViewById(R.id.button3);
btnDis = (Button)findViewById(R.id.button4);
brightness = (SeekBar)findViewById(R.id.seekBar);
lumn = (TextView)findViewById(R.id.lumn);
new ConnectBT().execute(); //Call the class to connect
//commands to be sent to bluetooth
btnOn.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
turnOnLed(); //method to turn on
}
});
btnOff.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
turnOffLed(); //method to turn off
}
});
btnDis.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
Disconnect(); //close connection
}
});
brightness.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
if (fromUser==true)
{
lumn.setText(String.valueOf(progress));
try
{
btSocket.getOutputStream().write(String.valueOf(progress).getBytes());
}
catch (IOException e)
{
}
}
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
private void Disconnect()
{
if (btSocket!=null) //If the btSocket is busy
{
try
{
btSocket.close(); //close connection
}
catch (IOException e)
{ msg("Error");}
}
finish(); //return to the first layout
}
private void turnOffLed()
{
if (btSocket!=null)
{
try
{
btSocket.getOutputStream().write("TF".toString().getBytes());
}
catch (IOException e)
{
msg("Error");
}
}
}
private void turnOnLed()
{
if (btSocket!=null)
{
try
{
btSocket.getOutputStream().write("TO".toString().getBytes());
}
catch (IOException e)
{
msg("Error");
}
}
}
// fast way to call Toast
private void msg(String s)
{
Toast.makeText(getApplicationContext(),s,Toast.LENGTH_LONG).show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_led_control, menu);
return true;
}
@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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
private class ConnectBT extends AsyncTask<Void, Void, Void> // UI thread
{
private boolean ConnectSuccess = true; //if it's here, it's almost connected
@Override
protected void onPreExecute()
{
progress = ProgressDialog.show(ledControl.this, "Connecting...", "Please wait!!!"); //show a progress dialog
}
@Override
protected Void doInBackground(Void... devices) //while the progress dialog is shown, the connection is done in background
{
try
{
if (btSocket == null || !isBtConnected)
{
myBluetooth = BluetoothAdapter.getDefaultAdapter();//get the mobile bluetooth device
BluetoothDevice dispositivo = myBluetooth.getRemoteDevice(address);//connects to the device's address and checks if it's available
btSocket = dispositivo.createInsecureRfcommSocketToServiceRecord(myUUID);//create a RFCOMM (SPP) connection
BluetoothAdapter.getDefaultAdapter().cancelDiscovery();
btSocket.connect();//start connection
}
}
catch (IOException e)
{
ConnectSuccess = false;//if the try failed, you can check the exception here
}
return null;
}
@Override
protected void onPostExecute(Void result) //after the doInBackground, it checks if everything went fine
{
super.onPostExecute(result);
if (!ConnectSuccess)
{
msg("Connection Failed. Is it a SPP Bluetooth? Try again.");
finish();
}
else
{
msg("Connected.");
isBtConnected = true;
}
progress.dismiss();
}
}
}
我正在进行的R.java如下
package com.technomentis.led;
public final class R {
public static final class attr {
}
public static final class mipmap {
public static final int cxemnet_logo=0x7f020000;
public static final int ic_action_search=0x7f020001;
public static final int ic_launcher=0x7f020002;
}
public static final class id {
public static final int btnOff=0x7f060000;
public static final int btnOn=0x7f060001;
public static final int listView=0x7f060002;
}
public static final class layout {
public static final int activity_device_list=0x7f030000;
}
public static final class string {
public static final int app_name=0x7f040000;
public static final int btn_OFF=0x7f040003;
public static final int btn_ON=0x7f040002;
public static final int title_activity_main=0x7f040001;
}
public static final class style {
public static final int AppTheme=0x7f050000;
}
}
任何人都可以帮我创建完整的R.java文件。我无法完成它。
顺便说一下我是android studio的新手。
答案 0 :(得分：0)
我定期遇到这个问题。构建 - ＆gt;重建项目和构建 - ＆gt;清洁项目总是为我解决问题。
答案 1 :(得分：0)
谢谢大家， 做完这个问题。只需创建新项目并复制粘贴的所有文件。 重建完成了所有的工作。
现在需要帮助 Error:(53, 43) error: cannot find symbol variable lumn