This is the login screen, which leads to the next screen(Chat Screen)
This is the Chat Screen- which I am unable to navigate to
我正在尝试实现聊天功能，其中登录和聊天屏幕都是片段。我没有任何错误。但是，该应用程序未导航到聊天屏幕。我不知道我失踪的地方。 任何建议都将不胜感激。
********登录片段********
public class LoginFragment extends Fragment {
private EditText mUsernameView;
private Button signInButton;
private String mUsername;
private Socket mSocket;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View loginview = inflater.inflate(R.layout.fragment_login, container, false);
ChatApplication app = (ChatApplication) getActivity().getApplication();
mSocket = app.getSocket();
// this is the login form
mUsernameView = (EditText) loginview.findViewById(R.id.username_input);
mUsernameView.setOnEditorActionListener(new TextView.OnEditorActionListener()
{
@Override
public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent)
{
if(id == R.id.login || id == EditorInfo.IME_NULL)
{
attemptLogin();
return true;
}
return false;
}
});
signInButton = (Button) loginview.findViewById(R.id.sign_in_button);
signInButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
attemptLogin();
}
});
mSocket.on("login",onLogin);
return loginview;
}
@Override
public void onDestroy() {
super.onDestroy();
mSocket.off("login", onLogin);
}
/*
This method attempts the following
1- clears the error message/resets the error message.
2- checks if the user has entered valid username
3- attempts user login
*/
private void attemptLogin()
{
mUsernameView.setError(null); //1
String username = mUsernameView.getText().toString().trim();
if(TextUtils.isEmpty(username)) //2
{
mUsernameView.setError("This field is required!");
mUsernameView.requestFocus();
return;
}
mUsername = username;
mSocket.emit("add user", username); //3
}
private Emitter.Listener onLogin = new Emitter.Listener()
{
@Override
public void call(Object... args)
{
JSONObject data = (JSONObject) args[0];
int numUsers;
try
{
numUsers = data.getInt("numUsers");
}
catch (JSONException e)
{
return;
}
Intent intent = new Intent();
intent.putExtra("username",mUsername);
intent.putExtra("numUsers",numUsers);
getActivity().setResult(RESULT_OK,intent);
getActivity().finish();
}
};
}
**************聊天片段*************
public class ChatFragment extends Fragment
{
private static final int REQUEST_LOGIN = 1;
private static final int TYPING_TIMER_LENGTH = 600;
private RecyclerView mMessagesView;
private EditText mInputMessageView;
private List<Message> mMessages = new ArrayList<Message>();
private RecyclerView.Adapter mAdapter;
private boolean mTyping = false;
private Handler mTypingHandler = new Handler();
private String mUsername;
private Socket mSocket;
private Boolean isConnected = true;
public ChatFragment() {
super();
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
mAdapter = new MessageAdapter(context, mMessages);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
ChatApplication app = (ChatApplication) getActivity().getApplication();
mSocket = app.getSocket();
mSocket.on(Socket.EVENT_CONNECT,onConnect);
mSocket.on(Socket.EVENT_DISCONNECT,onDisconnect);
mSocket.on(Socket.EVENT_CONNECT_ERROR, onConnectError);
mSocket.on(Socket.EVENT_CONNECT_TIMEOUT, onConnectError);
mSocket.on("new message", onNewMessage);
mSocket.on("user joined", onUserJoined);
mSocket.on("user left", onUserLeft);
mSocket.on("typing", onTyping);
mSocket.on("stop typing", onStopTyping);
mSocket.connect();
startSignIn();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_chat, container, false);
}
@Override
public void onDestroy() {
super.onDestroy();
mSocket.disconnect();
mSocket.off(Socket.EVENT_CONNECT, onConnect);
mSocket.off(Socket.EVENT_DISCONNECT, onDisconnect);
mSocket.off(Socket.EVENT_CONNECT_ERROR, onConnectError);
mSocket.off(Socket.EVENT_CONNECT_TIMEOUT, onConnectError);
mSocket.off("new message", onNewMessage);
mSocket.off("user joined", onUserJoined);
mSocket.off("user left", onUserLeft);
mSocket.off("typing", onTyping);
mSocket.off("stop typing", onStopTyping);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mMessagesView = (RecyclerView) view.findViewById(R.id.messages);
mMessagesView.setLayoutManager(new LinearLayoutManager(getActivity()));
mMessagesView.setAdapter(mAdapter);
mInputMessageView = (EditText) view.findViewById(R.id.message_input);
mInputMessageView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView v, int id, KeyEvent event) {
if (id == R.id.send || id == EditorInfo.IME_NULL) {
attemptSend();
return true;
}
return false;
}
});
mInputMessageView.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (null == mUsername) return;
if (!mSocket.connected()) return;
if (!mTyping) {
mTyping = true;
mSocket.emit("typing");
}
mTypingHandler.removeCallbacks(onTypingTimeout);
mTypingHandler.postDelayed(onTypingTimeout, TYPING_TIMER_LENGTH);
}
@Override
public void afterTextChanged(Editable s) {
}
});
ImageButton sendButton = (ImageButton) view.findViewById(R.id.send_button);
sendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
attemptSend();
}
});
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (Activity.RESULT_OK != resultCode) {
getActivity().finish();
return;
}
mUsername = data.getStringExtra("username");
int numUsers = data.getIntExtra("numUsers", 1);
addLog(getResources().getString(R.string.message_welcome));
addParticipantsLog(numUsers);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// Inflate the menu; this adds items to the action bar if it is present.
inflater.inflate(R.menu.menu_main, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_leave) {
leave();
return true;
}
return super.onOptionsItemSelected(item);
}
private void addLog(String message) {
mMessages.add(new Message.Builder(Message.TYPE_LOG)
.message(message).build());
mAdapter.notifyItemInserted(mMessages.size() - 1);
scrollToBottom();
}
private void addParticipantsLog(int numUsers) {
addLog(getResources().getQuantityString(R.plurals.message_participants, numUsers, numUsers));
}
private void addMessage(String username, String message) {
mMessages.add(new Message.Builder(Message.TYPE_MESSAGE)
.username(username).message(message).build());
mAdapter.notifyItemInserted(mMessages.size() - 1);
scrollToBottom();
}
private void addTyping(String username) {
mMessages.add(new Message.Builder(Message.TYPE_ACTION)
.username(username).build());
mAdapter.notifyItemInserted(mMessages.size() - 1);
scrollToBottom();
}
private void removeTyping(String username) {
for (int i = mMessages.size() - 1; i >= 0; i--) {
Message message = mMessages.get(i);
if (message.getType() == Message.TYPE_ACTION && message.getUsername().equals(username)) {
mMessages.remove(i);
mAdapter.notifyItemRemoved(i);
}
}
}
private void attemptSend() {
if (null == mUsername) return;
if (!mSocket.connected()) return;
mTyping = false;
String message = mInputMessageView.getText().toString().trim();
if (TextUtils.isEmpty(message)) {
mInputMessageView.requestFocus();
return;
}
mInputMessageView.setText("");
addMessage(mUsername, message);
// perform the sending message attempt.
mSocket.emit("new message", message);
}
private void startSignIn() {
mUsername = null;
/* Error:
Intent intent = new Intent(getActivity(), LoginFragment.class);
startActivityForResult(intent, REQUEST_LOGIN);
*/
// Solution 1: for calling a fragment from a fragment
Intent intent = new Intent(getActivity(),LoginFragment.class);
getActivity().startActivityForResult(intent,REQUEST_LOGIN);
/*
// Solution 2: for calling a fragment from a fragment
LoginFragment loginFragment = new LoginFragment();
FragmentManager fManager = getFragmentManager();
FragmentTransaction fTransaction = fManager.beginTransaction();
fTransaction.replace(R.id.id_fragment_chat,loginFragment);
fTransaction.addToBackStack(null);
fTransaction.commit();
*/
}
private void leave() {
mUsername = null;
mSocket.disconnect();
mSocket.connect();
startSignIn();
}
private void scrollToBottom() {
mMessagesView.scrollToPosition(mAdapter.getItemCount() - 1);
}
private Emitter.Listener onConnect = new Emitter.Listener() {
@Override
public void call(Object... args) {
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
if(!isConnected) {
if(null!=mUsername)
mSocket.emit("add user", mUsername);
Toast.makeText(getActivity().getApplicationContext(),
R.string.connect, Toast.LENGTH_LONG).show();
isConnected = true;
}
}
});
}
};
.
.
.
}
答案 0 :(得分：1)
使用核心片段结构而不是使用直接扩展
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
/**
*
* This is main core fragment. All fragment defined in this project that extends this fragment.
*
* @author viral
*
*/
public class CoreFragment extends Fragment {
private static FragmentManager fm;
private CharSequence tabTitle;
/**
* This method switch fragment.
*
* @param fragment - from fragment
* @param viewReplace - Destination view/container
*
*/
public void switchFragment(Fragment fragment, int viewReplace){
try {
FragmentManager fragmentManager = getFragmentManager();
if(fragmentManager != null)
fm = fragmentManager;
fm.beginTransaction()
.replace(viewReplace, fragment)
.commit();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* This method switch fragment.
*
* @param fragment - from fragment
* @param viewReplace - Destination view/container
*
*/
public void switchFragmentWithBackstack(Fragment fragment, int viewReplace){
try {
FragmentManager fragmentManager = getFragmentManager();
if(fragmentManager != null)
fm = fragmentManager;
fm.beginTransaction()
.replace(viewReplace, fragment)
.addToBackStack(null)
.commit();
} catch (Exception e) {
e.printStackTrace();
}
}
}
然后根据您的应用程序要求使用switchFragment / switchFragmentWithBackstack方法。
你的所有片段扩展了CoreFragment
答案 1 :(得分：0)
关于你的private void startSignIn() { mUsername = null; Intent intent = new Intent(getActivity(), LoginFragment.class); startActivityForResult(intent, 0); } ...你想做什么？开始另一项活动？然后你应该调用这个活动，并在这个活动中添加这个片段。或者，如果你想在同一个活动中将一个片段替换为另一个片段，你应该这样做，而不是startActivity：
YourFragment fragment = new YourFragment();
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.fragmentContainer, fragment, YOUR_TAG)
.commit();