Java Android蓝牙发现不工作
我正在尝试定期列出可用的蓝牙设备。我们的想法是每4秒运行一次startDiscovery()功能,并列出可见的设备Java Android蓝牙发现不工作,java,android,Java,Android,我正在尝试定期列出可用的蓝牙设备。我们的想法是每4秒运行一次startDiscovery()功能,并列出可见的设备 package com.neondude.cupid; import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.content.BroadcastReceiver; import
package com.neondude.cupid;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.Handler;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.Timer;
import java.util.TimerTask;
public class MainActivity extends Activity {
Timer mTimer;
private ListView listView;
private ArrayList<String> mDeviceList = new ArrayList<String>();
private BluetoothAdapter mBluetoothAdapter;
private ArrayAdapter<String> BTArrayAdapter;
Handler mHandler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView);
BTArrayAdapter = new ArrayAdapter<String>(this,R.layout.list_view);
listView.setAdapter(BTArrayAdapter);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
}
private void startTimer(){
mTimer = new Timer();
mTimer.scheduleAtFixedRate(new Mytask(), 4000, 1000 * 5);
}
class Mytask extends TimerTask {
@Override
public void run(){
mHandler.post(new Runnable(){
@Override
public void run(){
find();
}
});
}
}
public void find(){
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
else {
BTArrayAdapter.clear();
mBluetoothAdapter.startDiscovery();
registerReceiver(mReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
}
mBluetoothAdapter.startDiscovery();
}
final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action))
{
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
short rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,Short.MIN_VALUE);
BTArrayAdapter.add(device.getName() + "\n" + device.getAddress() + "\n" + rssi);
BTArrayAdapter.notifyDataSetChanged();
}
}
};
@Override
protected void onDestroy() {
unregisterReceiver(mReceiver);
super.onDestroy();
}
}
package com.neondude.cupid;
导入android.app.Activity;
导入android.bluetooth.BluetoothAdapter;
导入android.bluetooth.bluetooth设备;
导入android.content.BroadcastReceiver;
导入android.content.Context;
导入android.content.Intent;
导入android.content.IntentFilter;
导入android.os.Bundle;
导入android.os.Handler;
导入android.widget.ArrayAdapter;
导入android.widget.ListView;
导入java.util.ArrayList;
导入java.util.Timer;
导入java.util.TimerTask;
公共类MainActivity扩展了活动{
定时器;
私有列表视图列表视图;
private ArrayList mDeviceList=new ArrayList();
私人蓝牙适配器mBluetoothAdapter;
专用阵列适配器BTArrayAdapter;
Handler mHandler=新的Handler();
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView=(listView)findViewById(R.id.listView);
BTArrayAdapter=新的ArrayAdapter(这个,R.layout.list\u视图);
setAdapter(BTArrayAdapter);
mBluetoothAdapter=BluetoothAdapter.getDefaultAdapter();
IntentFilter筛选器=新的IntentFilter(BluetoothDevice.ACTION\u已找到);
registerReceiver(mrReceiver,过滤器);
}
私有void startTimer(){
mTimer=新计时器();
mTimer.scheduleAtFixedRate(newmytask(),40001000*5);
}
类Mytask扩展TimerTask{
@凌驾
公开募捐{
mHandler.post(新Runnable(){
@凌驾
公开募捐{
查找();
}
});
}
}
公共无效查找(){
if(mBluetoothAdapter.isDiscovering()){
mBluetoothAdapter.cancelDiscovery();
}
否则{
BTArrayAdapter.clear();
mBluetoothAdapter.startDiscovery();
registerReceiver(mReceiver,newintentfilter(BluetoothDevice.ACTION_-FOUND));
}
mBluetoothAdapter.startDiscovery();
}
最终广播接收器mReceiver=新广播接收器(){
公共void onReceive(上下文、意图){
String action=intent.getAction();
if(BluetoothDevice.ACTION_FOUND.equals(ACTION))
{
BluetoothDevice=intent.getParcelableExtra(BluetoothDevice.EXTRA\u设备);
short-rssi=intent.getShortExtra(BluetoothDevice.EXTRA\rssi,short.MIN\u值);
BTArrayAdapter.add(device.getName()+“\n”+device.getAddress()+“\n”+rssi);
BTArrayAdapter.notifyDataSetChanged();
}
}
};
@凌驾
受保护的空onDestroy(){
未注册接收人(mReceiver);
super.ondestory();
}
}
我在timertask处理程序中包含了startDiscovery()函数。但当我执行此操作时,设备和未在我的列表视图中列出。您应该检查蓝牙是否已打开,如果已关闭,请用户打开:
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
else{
startTimer();
}
您可以在ActivityResult()上启动计时器
startTimer()
函数从未被调用,因此timerTask不会开始。在运行应用程序之前,我打开了蓝牙。当startDiscovery()
函数超出timerTask时,我可以列出设备。是否需要取消查找并每5秒重新启动一次?感谢您指出这一点。我发现了问题,我没有在任何地方调用startimer()函数。
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// Check which request we're responding to
if (resultCode == RESULT_OK) {
// The user turn on the bluetooth
startTimer();
}
}
}