早上好，
我在使用蓝牙设备填写列表时遇到问题。 智能手机正在使用蓝牙搜索附近的蓝牙设备并将其添加到listView。如果设备已与手机配对，则“（已配对）”字符串将添加到设备名称中。
在找到最后一个BT-Devices之后，调试器跳转到looper类并停留在：
public static void loop() {
throw new RuntimeException("Stub!");
}
之后我收到此错误：
10-24 10:42:40.433 19279-19279/com.example.tut1 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.tut1, PID: 19279
java.lang.RuntimeException: Error receiving broadcast Intent { act=android.bluetooth.device.action.FOUND flg=0x10 (has extras) } in com.example.tut1.Bluetooth$1@d32059a
at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:1132)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6121)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at com.example.tut1.Bluetooth$1.onReceive(Bluetooth.java:121)
at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:1122)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6121)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)
这是我的代码：
private void init(){
listView = (ListView)findViewById(R.id.listView);
listView.setOnItemClickListener(this);
listAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,0);
listView.setAdapter(listAdapter);
btAdapter = BluetoothAdapter.getDefaultAdapter();
pairedDevices = new ArrayList<String>();
filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
devices = new ArrayList<BluetoothDevice>();
receiver = new BroadcastReceiver(){
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)){
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
devices.add(device);
String s = "";
for(int a=0;a<pairedDevices.size();a++){
if (device.getName().equals(pairedDevices.get(a))){
//append
s = "(Paired)";
break;
}
}
listAdapter.add(device.getName()+" "+s+" "+"\n"+device.getAddress());
}else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)){
}else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
}else if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)){
if (btAdapter.getState() == btAdapter.STATE_OFF){
turnOnBT();
}
}
}
};
registerReceiver(receiver, filter);
IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
registerReceiver(receiver, filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(receiver, filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
}
非常感谢＆amp;有一个伟大的！