getActivity() 它不适用于适配器

Question

这是我的代码。在 itemClickListener 部分，我调用了一个适配器，但我想它需要另一个参数，问题是我不知道它是什么

public class Lista_Activity extends Activity implements OnItemClickListener {

ArrayAdapter<String> listAdapter;
ListView listView;
BluetoothAdapter btAdapter;
Set<BluetoothDevice> devicesArray;
ArrayList<String> pairedDevices;
ArrayList<BluetoothDevice> devices;
public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
protected static final int SUCCESS_CONNECT = 0;
protected static final int MESSAGE_READ = 1;
IntentFilter filter;
BroadcastReceiver receiver;
String tag = "debugging";
Handler mHandler = new Handler(){
 @Override
 public void handleMessage(Message msg){
  // TODO Auto-generated method stub
  Log.i(tag, "in handler");
  super.handleMessage(msg);
  switch(msg.what){
  case SUCCESS_CONNECT:
   // DO something
   ConnectedThread connectedThread = new ConnectedThread((BluetoothSocket)msg.obj);
   Toast.makeText(getApplicationContext(), "CONECTADO", 0).show();
   String s = "Conexion realizada";
   connectedThread.write(s.getBytes());
   Log.i(tag, "Conectado");
   break;
  case MESSAGE_READ:
   byte[] readBuf = (byte[])msg.obj;
   String string = new String(readBuf);
   Toast.makeText(getApplicationContext(), string, 0).show();
   break;
  }
 }
};
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.lista);
    init();
    if(btAdapter==null){
     Toast.makeText(getApplicationContext(), "No se detectan dispositivos Bluetooth", 0).show();
     finish();
    }
    else{
     if(!btAdapter.isEnabled()){
      turnOnBT();
     }
     
     getPairedDevices();
     startDiscovery();
    }


}
private void startDiscovery() {
 // TODO Auto-generated method stub
 btAdapter.cancelDiscovery();
 btAdapter.startDiscovery();
 
}
private void turnOnBT() {
 // TODO Auto-generated method stub
 Intent intent =new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(intent, 1);
}
private void getPairedDevices() { //AGREGAMOS LOS DISPOSITIVOS CERCANOS A LA LISTA
 // TODO Auto-generated method stub
 devicesArray = btAdapter.getBondedDevices();
 if(devicesArray.size()>0){
  for(BluetoothDevice device:devicesArray){
   pairedDevices.add(device.getName());
   
  }
 }
}
private void init() {
 // TODO Auto-generated method stub
 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) {
   // TODO Auto-generated method stub
   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 = "(Agregado)";
      break;
     }
    }
    listAdapter.add(device.getName()+s+"\n"+"Dirección MAC: ("+device.getAddress()+")");
   }
   else if(BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)){
    // run some code
   }
   else if(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
    // run some code
   }
   else if(BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)){
    if(btAdapter.getState() == btAdapter.STATE_OFF){
     turnOnBT();
    }
   }
  }
 };
 registerReceiver(receiver, filter);
  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);
 registerReceiver(receiver, filter);
}


@Override
protected void onPause() {
 // TODO Auto-generated method stub
 super.onPause();
 unregisterReceiver(receiver);
}

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  // TODO Auto-generated method stub
  super.onActivityResult(requestCode, resultCode, data);
  if(resultCode == RESULT_CANCELED){
   Toast.makeText(getApplicationContext(), "Bluetooth must be enabled to continue", Toast.LENGTH_SHORT).show();
   finish();
  }
 }
 private void cargarLista(){
 Adapter_lista adapter = new Adapter_lista(getActivity());
 
    listView.setAdapter(adapter);
    listView.setOnItemClickListener(new OnItemClickListener() {
     @Override
 public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
   long arg3) {
  // TODO Auto-generated method stub
  
  if(btAdapter.isDiscovering()){
   btAdapter.cancelDiscovery();
  }
  if(listAdapter.getItem(arg2).contains("Agregado")){
   BluetoothDevice selectedDevice = devices.get(arg2);
   ConnectThread connect = new ConnectThread(selectedDevice);
   connect.start();
   Log.i(tag, "in click listener");
   
  }
  else{
   BluetoothDevice selectedDevice = devices.get(arg2);
   ConnectThread connect = new ConnectThread(selectedDevice);
   connect.start();
   Log.i(tag, "in click listener");
   Toast.makeText(getApplicationContext(), "Agregando dispositivo...", 0).show();
  }
  }
     });
    }
 
 private class ConnectThread extends Thread {
 
  private final BluetoothSocket mmSocket;
     private final BluetoothDevice mmDevice;
  
     public ConnectThread(BluetoothDevice device) {
         // Usa un objeto temporal que despues se asigna a mmSocket,
         BluetoothSocket tmp = null;
         mmDevice = device;
         Log.i(tag, "construct");
         // Get a BluetoothSocket to connect with the given BluetoothDevice
         try {
             // MY_UUID es el UUID string de la app, tambien usado por el server code
             tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
         } catch (IOException e) { 
          Log.i(tag, "get socket failed");
          
         }
         mmSocket = tmp;
     }
  
     public void run() {
         // Cancel discovery because it will slow down the connection
         btAdapter.cancelDiscovery();
         Log.i(tag, "connect - run");
         try {
             // Connect the device through the socket. This will block
             // until it succeeds or throws an exception
             mmSocket.connect();
             Log.i(tag, "connect - succeeded");
         } catch (IOException connectException) { Log.i(tag, "connect failed");
             // Unable to connect; close the socket and get out
             try {
                 mmSocket.close();
             } catch (IOException closeException) { }
             return;
         }
  
         // Do work to manage the connection (in a separate thread)
    
         mHandler.obtainMessage(SUCCESS_CONNECT, mmSocket).sendToTarget();
     }
  


  /** Will cancel an in-progress connection, and close the socket */
     public void cancel() {
         try {
             mmSocket.close();
         } catch (IOException e) { }
     }
 }

 private class ConnectedThread extends Thread {
     private final BluetoothSocket mmSocket;
     private final InputStream mmInStream;
     private final OutputStream mmOutStream;
  
     public ConnectedThread(BluetoothSocket socket) {
         mmSocket = socket;
         InputStream tmpIn = null;
         OutputStream tmpOut = null;
  
         // Get the input and output streams, using temp objects because
         // member streams are final
         try {
             tmpIn = socket.getInputStream();
             tmpOut = socket.getOutputStream();
         } catch (IOException e) { }
  
         mmInStream = tmpIn;
         mmOutStream = tmpOut;
     }
  
     public void run() {
         byte[] buffer;  // buffer store for the stream
         int bytes; // bytes returned from read()

         // Keep listening to the InputStream until an exception occurs
         while (true) {
             try {
                 // Read from the InputStream
              buffer = new byte[1024];
                 bytes = mmInStream.read(buffer);
                 // Send the obtained bytes to the UI activity
                 mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
                         .sendToTarget();
                
             } catch (IOException e) {
                 break;
             }
         }
     }
  
     /* Call this from the main activity to send data to the remote device */
     public void write(byte[] bytes) {
         try {
             mmOutStream.write(bytes);
         } catch (IOException e) { }
     }
  
     /* Call this from the main activity to shutdown the connection */
     public void cancel() {
         try {
             mmSocket.close();
         } catch (IOException e) { }
     }
 }

 @Override
 public void onItemClick(AdapterView<?> parent, View view, int position,
   long id) {
  // TODO Auto-generated method stub
  
 }
}

线路是 Adapter_lista 适配器...

Answer 1

我认为错误在于

Adapter_lista adapter = new Adapter_lista(getActivity());

改为

Adapter_lista adapter = new Adapter_lista(Lista_Activity.this);

希望它能解决您的问题。另请检查您的适配器构造函数及其参数。

Answer 2

将 getActivity() 更改为 Lista_Activity.this

getActivity() 用于 Fragments

getActivity() 它不适用于适配器

getActivity() it's not working with adapter

android

listview

adapter