【发布时间】:2021-09-27 22:41:30
【问题描述】:
MainActivity.java 这是我的 MainActivity.java 代码。
public class MainActivity extends AppCompatActivity {
private AppBarConfiguration mAppBarConfiguration;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
mAppBarConfiguration = new AppBarConfiguration.Builder(
R.id.nav_home, R.id.nav_courses, R.id.nav_practice_ques, R.id.nav_contact_us)
.setDrawerLayout(drawer)
.build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onSupportNavigateUp() {
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
return NavigationUI.navigateUp(navController, mAppBarConfiguration)
|| super.onSupportNavigateUp();
}
}
Courses.java(片段 A) 在 Courses.java 中,我试图通过列表视图调用另一个片段 courseDetails.java。我想在 courseDetails.java 中显示一个新的列表视图 之后,我从这个 (courseDetails.java) 调用一个新活动。
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_courses, container, false);
ListView coursesListView = view.findViewById(R.id.coursesListView);
ArrayList<String> courses = new ArrayList<>();
courses.add("Science");
courses.add("Mathematics");
courses.add("English");
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_checked, courses);
coursesListView.setAdapter(arrayAdapter);
coursesListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
courseDetails courseDetails = new courseDetails();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.courseLayout, courseDetails);
transaction.commit();
}
});
return view;
}
courseDetails.java(片段 B)
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_course_details, container, false);
ListView courseDetailView = view.findViewById(R.id.courseDetailView);
ArrayList<String> courseDetail = new ArrayList<>();
courseDetail.add("Physics");
courseDetail.add("Chemistry");
courseDetail.add("Biology");
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_checked, courseDetail);
courseDetailView.setAdapter(arrayAdapter);
courseDetailView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent intent = new Intent (view.getContext(), coursePlayer.class);
startActivity(intent);
}
});
return view;
}
当我点击科学时,我应该只看到新的列表视图(即物理、化学、生物学)。但是我得到了一个覆盖在前一个列表上的新列表。
我该如何解决这个问题? 提前致谢
【问题讨论】:
-
你是如何展示你的原始片段的?我认为它不在与
R.id.courseLayout对应的容器中。 -
原始片段是使用导航菜单从主活动中调用的。
标签: java android listview onclick fragment