我试图直接从Android教程中使用MyBluetoothService类，并按照文本的建议从主活动中调用write方法。我想了解一些关于如何将字符串从主活动传递到write方法并将其发送到连接的蓝牙设备的指导。
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答案 0 :(得分：0)
此代码将帮助您查找周围的所有设备
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
public class DeviceList extends AppCompatActivity {
ListView blist;
Button b;
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);
b=(Button)findViewById(R.id.button);
blist=(ListView)findViewById(R.id.listView);
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);
}
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
pairedDevices();
}
});
}
private void pairedDevices()
{
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);
blist.setAdapter(adapter);
blist.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);
}
};
}
此代码有助于将消息发送到已连接的设备
public class ledControl extends AppCompatActivity {
Button btnOn, btnOff, btnDis;
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);
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
}
});
}
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("F".toString().getBytes());
//Log.e("message",)
}
catch (IOException e)
{
msg("Error");
}
}
}
private void turnOnLed()
{
if (btSocket!=null)
{
try
{
//Toast.makeText(ledControl.this,"oning",Toast.LENGTH_SHORT).show();
btSocket.getOutputStream().write("O".toString().getBytes());
Log.e("message",btSocket.toString());
}
catch (IOException e)
{
msg("Error");
}
}
}
// fast way to call Toast
private void msg(String s)
{
Toast.makeText(getApplicationContext(),s,Toast.LENGTH_LONG).show();
}
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();
}
}
}