Question

我有一个NavigationDrawer应用程序，但是没有调用onNavigationItemSelected方法。抽屉正常工作，当选择一个项目时，抽屉关闭，但视图没有加载/更改

我的主要课程

Java Compiler

我的主要XML

public class BRGO extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_brgo);
        News initial = new News();
        FragmentTransaction transfer = getSupportFragmentManager().beginTransaction();
        transfer.replace(R.id.fragmentcontainer, initial);
        transfer.commit();
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState(); 
        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.brgo, menu);

        return true;
    }

    @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();
        SharedPreferences sharedPref =  getPreferences(Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPref.edit();
        //noinspection SimplifiableIfStatement
        if (id == R.id.S14273) {
         editor.putInt("School", 14273);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14276){
            editor.putInt("School", 14276);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14274){
            editor.putInt("School", 14274);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14271){
            editor.putInt("School", 14271);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14278){
            editor.putInt("School", 14278);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14277){
            editor.putInt("School", 14273);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14275){
            editor.putInt("School", 14275);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14272){
            editor.putInt("School", 14272);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14269){
            editor.putInt("School", 14269);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14268){
            editor.putInt("School", 14268);
            editor.commit();
            return true;
        }
        else if(id == R.id.S14264){
            editor.putInt("School", 14264);
            editor.commit();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        Fragment fragment;
        switch (id) {
            case R.id.nav_News:
                fragment = News.newInstance();
                break;
            case R.id.nav_Calendar:
                fragment = Calendar.newInstance();
                break;
            case R.id.nav_Websites:
                fragment = Websites.newInstance();
                break;
            case R.id.nav_About:
                fragment = About.newInstance();
            default:
                fragment = News.newInstance();
                break;
        }
        FragmentTransaction transfer = getSupportFragmentManager().beginTransaction();
        transfer.replace(R.id.fragmentcontainer,fragment);
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

我的应用栏XML

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start"
    android:background="@color/colorPrimary">

    <include
        layout="@layout/app_bar_brgo"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header_brgo"
        app:menu="@menu/activity_brgo_drawer"
        app:itemTextColor="@color/colorPrimaryDark"
        app:itemBackground="@color/colorPrimary"
        android:background="@color/colorPrimary"/>
</android.support.v4.widget.DrawerLayout>

Answer 1

如果没有提交，FragmentTransaction就不完整。

改变这个：

FragmentTransaction transfer = getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer,fragment);

为：

FragmentTransaction transfer = getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer,fragment).commit();

onNavigationItemSelected未在导航抽屉中调用

1 个答案: