接收广播错误蓝牙发现 - 错误onRecieve（）方法，通过startDiscovery接收意图（）方法 [英] Receiving broadcast error for Bluetooth discovery - Error in onRecieve() method that receives intents by startDiscovery() Method
本文介绍了接收广播错误蓝牙发现 - 错误onRecieve（）方法，通过startDiscovery接收意图（）方法的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
您好我是新来的Android编程，我面临着设备扫描活动的一个问题。我想扫描所有蓝牙设备在附近，并且打印出来的UI。但我得到相同的运行时错误在<一个href=\"http://stackoverflow.com/questions/10376388/receiving-broadcast-error-for-bluetooth-discovery\">Receiving广播错误的蓝牙发现。请请请帮我调试我的code。
公共类MainActivity扩展ActionBarActivity { BluetoothAdapter mBluetoothAdapter;
私人INT REQUEST_ENABLE_BT = 1000;
公众的ArrayList＆LT;串GT; deviceArrayList =新的ArrayList＆LT;＆GT;（）;
公众的ArrayList＆LT;＆BluetoothDevice类GT; DEVICELIST =新的ArrayList＆LT;＆GT;（）; @覆盖
保护无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.activity_main）;
} @覆盖
保护无效onResume（）{
// TODO自动生成方法存根
super.onResume（）;
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter（）;
如果（mBluetoothAdapter == NULL）{
//设备不支持蓝牙
Toast.makeText（这一点，设备不支持蓝牙!!!，Toast.LENGTH_LONG）.show（）;
返回;
}
如果（！mBluetoothAdapter.isEnabled（））{
意图enableBtIntent =新意图（BluetoothAdapter.ACTION_REQUEST_ENABLE）;
startActivityForResult（enableBtIntent，REQUEST_ENABLE_BT）;
}
scanStart（）;
} 公共无效scanStart（）{
// TODO自动生成方法存根 //添加配对设备到ArrayList中
addPairedDevices（）; 如果（mBluetoothAdapter.isDiscovering（））{
mBluetoothAdapter.cancelDiscovery（）;
}
如果（mBluetoothAdapter.startDiscovery（）==真）{
Toast.makeText（这一点，搜索...，Toast.LENGTH_LONG）.show（）;
}
其他{
Toast.makeText（这一点，蓝牙适配器了NULL值，Toast.LENGTH_SHORT）.show（）;
} //注册的BroadcastReceiver
IntentFilter的过滤器=新的IntentFilter（BluetoothDevice.ACTION_FOUND）;
this.registerReceiver（requestReciever，过滤器）; //不要忘记的onDestroy期间注销 尝试{
视频下载（12000）;
}赶上（InterruptedException的E）{
// TODO自动生成catch块
e.printStackTrace（）;
} 在UI //打印设备列表
ListView控件LV =新的ListView（这一点）;
ArrayAdapter＆LT;串GT; listAdapter =新ArrayAdapter＆LT;＆GT;（这一点，R.layout.print_device_list，deviceArrayList）;
lv.setAdapter（listAdapter）;
的setContentView（LV）;
如果（deviceArrayList.size（）＆下; = 0）{
Toast.makeText（这一点，未找到设备...，Toast.LENGTH_LONG）.show（）;
}
}
公共无效addPairedDevices（）{
// TODO自动生成方法存根
//获取配对设备
SET＆LT;＆BluetoothDevice类GT; pairedDevices = mBluetoothAdapter.getBondedDevices（）;
//如果有配对设备
如果（pairedDevices.size（）大于0）{
//循环配对设备
对于（BluetoothDevice类设备：pairedDevices）{
//添加名称和地址到一个数组适配器在ListView显示
deviceArrayList.add（device.getName（）+\\ n+ device.getAddress（）+\\ n+ device.getUuids（）[0] .getUuid（））;
deviceList.add（设备）;
}
}
}
私人广播接收器requestReciever =新的广播接收器（）{ 公共无效的onReceive（上下文的背景下，意图意图）{
如果（意向== NULL）{
返回;
}
字符串行动= intent.getAction（）; 如果（BluetoothDevice.ACTION_FOUND.equals（动作））{
Log.d（BT，设备中找到）;
BluetoothDevice类设备= intent.getParcelableExtra（BluetoothDevice.EXTRA_DEVICE）;
如果（设备！= NULL）{
如果（device.getName（）=空＆放大器;！＆放大器; device.getName（）长度（）大于0）{
deviceArrayList.add（device.getName（）+\\ n+ device.getAddress（）+\\ n+ device.getUuids（）[0] .getUuid（））;
deviceList.add（设备）;
}
}
}
};
};
@覆盖
保护无效的onActivityResult（INT申请code，INT结果code，意图数据）{
// TODO自动生成方法存根
super.onActivityResult（要求code，结果code，数据）; 如果（要求code == REQUEST_ENABLE_BT）{
如果（结果code == Activity.RESULT_CANCELED）{
Toast.makeText（这一点，UESR想不打开蓝牙!!!，Toast.LENGTH_LONG）.show（）;
返回;
}
}
} @覆盖
保护无效的onDestroy（）{
// TODO自动生成方法存根
super.onDestroy（）;
如果（mBluetoothAdapter！= NULL）{
mBluetoothAdapter.cancelDiscovery（）;
}
如果（requestReciever！= NULL）
unregisterReceiver（requestReciever）;
Toast.makeText（这一点，蓝牙应用程序已停止，Toast.LENGTH_LONG）.show（）;
}
}
解决方案
device.getUuids（） - 在这里你有一个空，这就是为什么你在这里有一个错误。
检查这个变量beforе使用它。
Hi I am new to android programming and i am facing a problem in device scan activity. I want to scan all bluetooth devices in vicinity and print them on UI. But i am getting the same run time error as in Receiving broadcast error for Bluetooth discovery. Please, please please help me to debug my code.
public class MainActivity extends ActionBarActivity {
BluetoothAdapter mBluetoothAdapter;
private int REQUEST_ENABLE_BT = 1000;
public ArrayList<String> deviceArrayList = new ArrayList<>();
public ArrayList<BluetoothDevice> deviceList = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
// Device does not support Bluetooth
Toast.makeText(this, "Device Doesn't Support Bluetooth!!!", Toast.LENGTH_LONG).show();
return;
}
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT );
}
scanStart();
}
public void scanStart() {
// TODO Auto-generated method stub
//Adding Paired Devices into ArrayList
addPairedDevices();
if(mBluetoothAdapter.isDiscovering()){
mBluetoothAdapter.cancelDiscovery();
}
if(mBluetoothAdapter.startDiscovery() == true){
Toast.makeText(this, "Searching...", Toast.LENGTH_LONG).show();
}
else{
Toast.makeText(this, "Bluetooth Adapter got Null Value", Toast.LENGTH_SHORT).show();
}
// Register the BroadcastReceiver
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(requestReciever, filter); // Don't forget to unregister during onDestroy
try {
Thread.sleep(12000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//Printing Device List on UI
ListView lv = new ListView(this);
ArrayAdapter<String> listAdapter = new ArrayAdapter<>(this, R.layout.print_device_list, deviceArrayList);
lv.setAdapter(listAdapter);
setContentView(lv);
if(deviceArrayList.size()<=0){
Toast.makeText(this, "No Devices Found...", Toast.LENGTH_LONG).show();
}
}
public void addPairedDevices() {
// TODO Auto-generated method stub
// get paired devices
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
// If there are paired devices
if (pairedDevices.size() > 0) {
// Loop through paired devices
for (BluetoothDevice device : pairedDevices) {
// Add the name and address to an array adapter to show in a ListView
deviceArrayList.add(device.getName() + "\n" + device.getAddress() + "\n" + device.getUuids()[0].getUuid());
deviceList.add(device);
}
}
}
private BroadcastReceiver requestReciever = new BroadcastReceiver(){
public void onReceive(Context context, Intent intent) {
if (intent == null) {
return;
}
String action = intent.getAction();
if(BluetoothDevice.ACTION_FOUND.equals(action)){
Log.d("BT", "Device Found");
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if(device!=null){
if(device.getName() != null && device.getName().length() > 0){
deviceArrayList.add(device.getName()+"\n"+device.getAddress()+"\n"+device.getUuids()[0].getUuid());
deviceList.add(device);
}
}
}
};
};
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == REQUEST_ENABLE_BT){
if(resultCode == Activity.RESULT_CANCELED){
Toast.makeText(this, "Uesr Doesn't want to switch on Bluetooth!!!", Toast.LENGTH_LONG).show();
return;
}
}
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
if(mBluetoothAdapter != null){
mBluetoothAdapter.cancelDiscovery();
}
if(requestReciever!=null)
unregisterReceiver(requestReciever);
Toast.makeText(this, "Bluetooth App Stopped", Toast.LENGTH_LONG).show();
}
}
解决方案
device.getUuids() - here you have a Null, that is why you have an error here.
Check this variable beforе using it.
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