我创建了简单的聊天应用程序，它包含一些处理所有聊天消息的ListView，但每个ListView都在另一个类中定义。我想从溢出菜单中清除清除聊天中的列表项，该菜单存在于主活动中。我怎样才能做到这一点？
以下是我的主要活动WiFiServiceDiscoveryActivity：
public class WiFiServiceDiscoveryActivity extends AppCompatActivity implements
DeviceClickListener, Handler.Callback, MessageTarget,
ConnectionInfoListener {
public static final String TAG = "wifidirectdemo";
// TXT RECORD properties
public static final String TXTRECORD_PROP_AVAILABLE = "available";
public static final String SERVICE_INSTANCE = " ";
public static final String SERVICE_REG_TYPE = "_presence._tcp";
public static final int MESSAGE_READ = 0x400 + 1;
public static final int MY_HANDLE = 0x400 + 2;
private WifiP2pManager manager;
static final int SERVER_PORT = 4545;
private final IntentFilter intentFilter = new IntentFilter();
private Channel channel;
private BroadcastReceiver receiver = null;
private WifiP2pDnsSdServiceRequest serviceRequest;
private Handler handler = new Handler(this);
private WiFiChatFragment chatFragment;
private WiFiDirectServicesList servicesList;
private TextView statusTxtView;
Toolbar toolbar;
private String friend;
private WiFiP2pService service;
WiFiChatFragment listView;
WiFiChatFragment.ChatMessageAdapter a;
public Handler getHandler() {
return handler;
}
public void setHandler(Handler handler) {
this.handler = handler;
}
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
toolbar=(Toolbar)findViewById(R.id.toolbar);
statusTxtView = (TextView) findViewById(R.id.status_text);
intentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
intentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
intentFilter
.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
intentFilter
.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
manager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
channel = manager.initialize(this, getMainLooper(), null);
startRegistrationAndDiscovery();
servicesList = new WiFiDirectServicesList();
getFragmentManager().beginTransaction()
.add(R.id.container_root, servicesList, "services").commit();
setSupportActionBar(toolbar);
}
@Override
protected void onRestart() {
Fragment frag = getFragmentManager().findFragmentByTag("services");
if (frag != null) {
getFragmentManager().beginTransaction().remove(frag).commit();
}
super.onRestart();
}
@Override
protected void onStop() {
if (manager != null && channel != null) {
manager.removeGroup(channel, new ActionListener() {
@Override
public void onFailure(int reasonCode) {
Log.d(TAG, "Disconnect failed. Reason :" + reasonCode);
}
@Override
public void onSuccess() {
}
});
}
super.onStop();
}
/**
* Registers a local service and then initiates a service discovery
*/
private void startRegistrationAndDiscovery() {
Map<String, String> record = new HashMap<String, String>();
record.put(TXTRECORD_PROP_AVAILABLE, "visible");
WifiP2pDnsSdServiceInfo service = WifiP2pDnsSdServiceInfo.newInstance(
SERVICE_INSTANCE, SERVICE_REG_TYPE, record);
manager.addLocalService(channel, service, new ActionListener() {
@Override
public void onSuccess() {
//appendStatus("Added Local Service");
}
@Override
public void onFailure(int error) {
// appendStatus("Failed to add a service");
}
});
discoverService();
}
private void discoverService() {
/*
* Register listeners for DNS-SD services. These are callbacks invoked
* by the system when a service is actually discovered.
*/
manager.setDnsSdResponseListeners(channel,
new DnsSdServiceResponseListener() {
@Override
public void onDnsSdServiceAvailable(String instanceName,
String registrationType, WifiP2pDevice srcDevice) {
// A service has been discovered. Is this our app?
if (instanceName.equalsIgnoreCase(SERVICE_INSTANCE)) {
// update the UI and add the item the discovered
// device.
WiFiDirectServicesList fragment = (WiFiDirectServicesList) getFragmentManager()
.findFragmentByTag("services");
if (fragment != null) {
WiFiDevicesAdapter adapter = ((WiFiDevicesAdapter) fragment
.getListAdapter());
service = new WiFiP2pService();
service.device = srcDevice;
service.instanceName = instanceName;
service.serviceRegistrationType = registrationType;
adapter.add(service);
adapter.notifyDataSetChanged();
Log.d(TAG, "onBonjourServiceAvailable "
+ instanceName);
}
}
}
}, new DnsSdTxtRecordListener() {
/**
* A new TXT record is available. Pick up the advertised
* buddy name.
*/
@Override
public void onDnsSdTxtRecordAvailable(
String fullDomainName, Map<String, String> record,
WifiP2pDevice device) {
Log.d(TAG,
device.deviceName + " is "
+ record.get(TXTRECORD_PROP_AVAILABLE));
}
});
// After attaching listeners, create a service request and initiate
// discovery.
serviceRequest = WifiP2pDnsSdServiceRequest.newInstance();
manager.addServiceRequest(channel, serviceRequest,
new ActionListener() {
@Override
public void onSuccess() {
// appendStatus("Added service discovery request");
}
@Override
public void onFailure(int arg0) {
appendStatus("Failed adding service discovery request");
}
});
manager.discoverServices(channel, new ActionListener() {
@Override
public void onSuccess() {
//appendStatus("Service discovery initiated");
}
@Override
public void onFailure(int arg0) {
appendStatus("Service discovery failed");
}
});
}
@Override
public void connectP2p(WiFiP2pService service) {
WifiP2pConfig config = new WifiP2pConfig();
config.deviceAddress = service.device.deviceAddress;
config.wps.setup = WpsInfo.PBC;
if (serviceRequest != null)
manager.removeServiceRequest(channel, serviceRequest,
new ActionListener() {
@Override
public void onSuccess() {
}
@Override
public void onFailure(int arg0) {
}
});
manager.connect(channel, config, new ActionListener() {
@Override
public void onSuccess() {
appendStatus("Connecting to service");
}
@Override
public void onFailure(int errorCode) {
appendStatus("Failed connecting to service");
}
});
}
@Override
public boolean handleMessage(Message msg) {
switch (msg.what) {
case MESSAGE_READ:
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
String readMessage = new String(readBuf, 0, msg.arg1);
Log.d(TAG, readMessage);
(chatFragment).pushMessage("Friend :" + readMessage);
break;
case MY_HANDLE:
Object obj = msg.obj;
(chatFragment).setChatManager((ChatManager) obj);
}
return true;
}
@Override
public void onResume() {
super.onResume();
receiver = new HomeActivity(manager, channel, this);
registerReceiver(receiver, intentFilter);
}
@Override
public void onPause() {
super.onPause();
unregisterReceiver(receiver);
}
@Override
public void onConnectionInfoAvailable(WifiP2pInfo p2pInfo) {
Thread handler = null;
if (p2pInfo.isGroupOwner) {
Log.d(TAG, "Connected as group owner");
try {
handler = new GroupOwnerSocketHandler(
((MessageTarget) this).getHandler());
handler.start();
} catch (IOException e) {
Log.d(TAG,
"Failed to create a server thread - " + e.getMessage());
return;
}
} else {
Log.d(TAG, "Connected as peer");
handler = new ClientSocketHandler(
((MessageTarget) this).getHandler(),
p2pInfo.groupOwnerAddress);
handler.start();
}
chatFragment = new WiFiChatFragment();
getFragmentManager().beginTransaction()
.replace(R.id.container_root, chatFragment).commit();
statusTxtView.setVisibility(View.GONE);
}
public void appendStatus(String status) {
String current = statusTxtView.getText().toString();
statusTxtView.setText(current + "\n" + status);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_settings:
Toast.makeText(this, "Settings selected", Toast.LENGTH_SHORT)
.show();
break;
case R.id.clean:
Toast.makeText(this, "Clear Chat", Toast.LENGTH_SHORT).show();
break;
default:
break;
}
return true;
}
}
另一个名为ListView的{{1}}类：
WiFiChatFragment答案 0 :(得分：0)
嘿Adesh你可以在点击溢出项目时执行此操作：
再次调用setListAdapter（）。这次是一个空的ArrayList。
希望它有所帮助！