问题
All my pages use onSupportNavigateUp() function with the same method and it's working. However when I tried to implement in my LessonActivity.java it's not working. Any ideas? It's it because of WebView?
My current working codes for LessonActivity.java:
package com.activity.lesson;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.design.widget.BottomSheetBehavior;
import android.support.design.widget.BottomSheetDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.AppCompatRatingBar;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.PopupMenu;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ServerValue;
import com.google.firebase.database.ValueEventListener;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.material.components.R;
import com.material.components.activity.pastyears.PastYears;
import com.material.components.activity.practice.Practice;
import com.material.components.adapter.AdapterQuestionToTeacher;
import com.material.components.model.Lessons;
import com.material.components.model.QuestionsToTeacher;
import com.material.components.model.SubChapter;
import com.material.components.utils.Tools;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class LessonActivity extends AppCompatActivity{
public WebView contentWebView;
public ProgressBar progressBar;
public String chapterTitle;
private SharedPreferences analysisSharedPreferences;
private SharedPreferences.Editor editorAnalysisPreferences;
private BottomSheetBehavior mBehavior;
private BottomSheetDialog mBottomSheetDialog;
private View bottom_sheet;
private BottomNavigationView navigation;
public ArrayList<QuestionsToTeacher> questionsToTeacherList = new ArrayList<>();
private AdapterQuestionToTeacher adapterQuestionToTeacher;
private RecyclerView questionListRecyclerView;
private String subjectId;
private String chapterId;
private String subchapterId;
private TextView question_content;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lesson);
contentWebView = findViewById(R.id.contentWebView);
progressBar = findViewById(R.id.progressBarContent);
question_content = findViewById(R.id.question_content);
Tools.setSystemBarColor(this,R.color.black);
String qContent = question_content.getText().toString().trim();
if(qContent.isEmpty())
{
question_content.setVisibility(View.GONE);
}else
{
question_content.setVisibility(View.VISIBLE);
}
initToolbar();
String subChapterId = getIntent().getStringExtra("subchapter_id");
getLessonData(subChapterId);
analysisSharedPreferences = getApplicationContext().getSharedPreferences("AnalysisSharedPreferences",MODE_PRIVATE);
editorAnalysisPreferences = analysisSharedPreferences.edit();
subjectId = analysisSharedPreferences.getString("subjectId","");
chapterId = analysisSharedPreferences.getString("chapterId","");
subchapterId = analysisSharedPreferences.getString("subchapterId","");
bottom_sheet = findViewById(R.id.bottom_sheet);
mBehavior = BottomSheetBehavior.from(bottom_sheet);
navigation = findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_question_list:
showQuestionList();
return true;
}
return false;
}
});
}
private void getQuestionList() {
GsonBuilder builder = new GsonBuilder();
final Gson gson = builder.create();
questionsToTeacherList.clear();
FirebaseDatabase firebaseDatabase = FirebaseDatabase.getInstance();
DatabaseReference databaseReference = firebaseDatabase.getReference();
FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
databaseReference.child("ask_teachers/students/"+firebaseAuth.getUid()+"/subjects/"+subjectId+"/chapters/"+chapterId+"/subchapters/"+subchapterId+"/questions").addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot snapshot: dataSnapshot.getChildren())
{
String dataReceived = gson.toJson(snapshot.getValue());
System.out.println(snapshot.getValue());
QuestionsToTeacher questionsToTeacher = gson.fromJson(dataReceived,QuestionsToTeacher.class);
questionsToTeacherList.add(questionsToTeacher);
}
adapterQuestionToTeacher.notifyDataSetChanged();
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
private void showQuestionList() {
if (mBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED) {
mBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
}
final View view = getLayoutInflater().inflate(R.layout.sheet_question_list, null);
adapterQuestionToTeacher = new AdapterQuestionToTeacher(questionsToTeacherList);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(LessonActivity.this);
questionListRecyclerView = view.findViewById(R.id.questionListRecyclerView);
questionListRecyclerView.setItemAnimator(new DefaultItemAnimator());
questionListRecyclerView.setNestedScrollingEnabled(false);
questionListRecyclerView.setHasFixedSize(true);
questionListRecyclerView.setLayoutManager(layoutManager);
questionListRecyclerView.setAdapter(adapterQuestionToTeacher);
adapterQuestionToTeacher.setOnClickListener(new AdapterQuestionToTeacher.OnClickListener() {
@Override
public void onItemClick(View view, QuestionsToTeacher obj, int pos) {
question_content.setVisibility(View.VISIBLE);
question_content.setText(obj.messages);
mBottomSheetDialog.dismiss();
}
});
(view.findViewById(R.id.bt_close)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mBottomSheetDialog.dismiss();
}
});
mBottomSheetDialog = new BottomSheetDialog(this);
mBottomSheetDialog.setContentView(view);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mBottomSheetDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
}
mBottomSheetDialog.show();
mBottomSheetDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
mBottomSheetDialog = null;
}
});
getQuestionList();
}
private void getLessonData(String subChapterId)
{
FirebaseDatabase.getInstance().getReference().child("lessons/"+subChapterId+"/lessons_data")
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String lessonDisplay = "";
for(DataSnapshot snapshot: dataSnapshot.getChildren())
{
System.out.println("lesson_inner_content");
System.out.println(snapshot.getValue());
lessonDisplay += snapshot.getValue();
}
contentWebView.getSettings().setJavaScriptEnabled(true);
contentWebView.setWebViewClient(new AppWebViewClients(progressBar));
contentWebView.loadData(String.valueOf(lessonDisplay),"text/html", "UTF-8");
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
public class AppWebViewClients extends WebViewClient {
private ProgressBar progressBar;
public AppWebViewClients(ProgressBar progressBar) {
this.progressBar=progressBar;
progressBar.setVisibility(View.VISIBLE);
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// TODO Auto-generated method stub
view.loadUrl(url);
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
// TODO Auto-generated method stub
super.onPageFinished(view, url);
progressBar.setVisibility(View.GONE);
}
}
private void initToolbar() {
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
chapterTitle = getIntent().getStringExtra("subChapterTitle");
setTitle(chapterTitle);
}
@Override
public boolean onSupportNavigateUp() {
onBackPressed();
return true;
}
public void openSubMenu(View v)
{
PopupMenu popup = new PopupMenu(v.getContext(), v);
MenuInflater inflater = popup.getMenuInflater();
inflater.inflate(R.menu.menu_lesson_more, popup.getMenu());
popup.show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_lesson,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if(id == R.id.askTeacher)
{
showQuestionEntryDialog();
}
if(id == R.id.practice)
{
Intent gotoPractice = new Intent(LessonActivity.this, Practice.class);
startActivity(gotoPractice);
}
if(id == R.id.pastYears)
{
Intent gotoPastYears = new Intent(LessonActivity.this, PastYears.class);
startActivity(gotoPastYears);
}
return true;
}
private void showQuestionEntryDialog() {
final Dialog dialog = new Dialog(this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE); // before
dialog.setContentView(R.layout.dialog_ask_teacher_question_entry);
dialog.setCancelable(true);
WindowManager.LayoutParams lp = new WindowManager.LayoutParams();
lp.copyFrom(dialog.getWindow().getAttributes());
lp.width = WindowManager.LayoutParams.WRAP_CONTENT;
lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
final EditText et_post = dialog.findViewById(R.id.et_post);
dialog.findViewById(R.id.bt_cancel).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dialog.dismiss();
}
});
dialog.findViewById(R.id.bt_submit).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String review = et_post.getText().toString().trim();
if (review.isEmpty()) {
Toast.makeText(getApplicationContext(), "Please fill review text", Toast.LENGTH_SHORT).show();
}else
{
submitQuestion(review, dialog);
}
}
});
dialog.show();
dialog.getWindow().setAttributes(lp);
}
private void submitQuestion(String message, final Dialog dialog)
{
FirebaseDatabase firebaseDatabase = FirebaseDatabase.getInstance();
FirebaseUser currentFirebaseUser = FirebaseAuth.getInstance().getCurrentUser();
String uuid = currentFirebaseUser.getUid();
DatabaseReference databaseReference = firebaseDatabase.getReference();
HashMap<Object,Object> messagesData = new HashMap<>();
messagesData.put("subject_id",subjectId);
messagesData.put("chapter_id",chapterId);
messagesData.put("subchapter_id",subchapterId);
messagesData.put("messages",message);
messagesData.put("status","pending");
messagesData.put("dt_added", ServerValue.TIMESTAMP);
databaseReference.child("ask_teachers/students/"+uuid+"/subjects/"+subjectId+"/chapters/"+chapterId+"/subchapters/"+subchapterId+"/questions/").push().setValue(messagesData, new DatabaseReference.CompletionListener(){
@Override
public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
Toast.makeText(LessonActivity.this, "Successfully added to Ask Teacher list", Toast.LENGTH_SHORT).show();
dialog.dismiss();
}
});
}
}
回答1:
onSupportNavigateUp() is not working because you're also overriding onOptionsItemSelected(). Since you return true; from onOptionsItemSelected(), you basically tell Android that you handle all item clicks by yourself and it doesn't need to do something.
You have two options now. Either call super.onOptionsItemSelected() like:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.askTeacher) {
showQuestionEntryDialog();
return true; // don't forget to return true after your action
}
// ... handle all your other items
return super.onOptionsItemSelected(item);
}
Or you handle the back button click by yourself:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
// navigate up on back button click
if (id == android.R.id.home) {
NavUtils.navigateUpFromSameTask(this);
return true;
}
// ... handle all your other items
return true;
}
By the way, I think overriding onSupportNavigateUp() is not needed at all. Up navigation works "out of the box" (at least for me), as long as I don't override onOptionsItemSelected() or call super.onOptionsItemSelected(item); from within it.
来源：https://stackoverflow.com/questions/48658698/onsupportnavigateup-function-not-working