想要添加主页并退出 onclick 方法

Question

在这里我想添加一个 home 和 exit 方法。当我按下退出选项时，应用程序将关闭（带有R.id.exit），当我按下主页按钮时，用户将进入主屏幕（带有R.id.homepage）。这是我的代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    FloatingActionButton fab = (FloatingActionButton) 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 = (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.main, 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();
    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();
    FragmentManager fragmentManager = getFragmentManager();
    if (id == R.id.homepage) {
    } else if (id == R.id.foodpage) {
        //handle the food page here
        fragmentManager.beginTransaction()
                .replace(R.id.content_frame
                        , new FirstFragment())
                .commit();
    } else if (id == R.id.schedulepage) {
        fragmentManager.beginTransaction()
                .replace(R.id.content_frame
                , new ScheduleFragment())
                .commit();
    } else if (id == R.id.emotionspage) {
        fragmentManager.beginTransaction()
                .replace(R.id.content_frame
                , new EmotionsFragment())
                .commit();
    } else if (id == R.id.basicneedspage) {
        fragmentManager.beginTransaction()
                .replace(R.id.content_frame
                , new BasicneedsFragment())
                .commit();
    } else if (id == R.id.exit) {
    }
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

Answer 1

你可以这样做

 @SuppressWarnings("StatementWithEmptyBody")
        @Override
        public boolean onNavigationItemSelected(MenuItem item) {
            // Handle navigation view item clicks here.
            int id = item.getItemId();
            FragmentManager fragmentManager = getFragmentManager();
            switch(id){
               case R.id.home:
                    //If you are in the same Activity 
                    fragmentManager.beginTransaction()
                        .replace(R.id.content_frame
                                , new YourHomeFragment())
                        .commit();
                    //If you are in other activity and you call from fragment home page , just make intent to your Activity which holds home page
                    Intent intent = new Intent(getActivity(),YourActivityWhichHoldHomePage.class);
                    startActivity(intent);
                  break;
               case R.id.foodpage:
                //handle the food page here
                fragmentManager.beginTransaction()
                        .replace(R.id.content_frame
                                , new FirstFragment())
                        .commit();
                  break;
               case R.id.schedulepage:
                   fragmentManager.beginTransaction()
                        .replace(R.id.content_frame
                        , new ScheduleFragment())
                        .commit();       
                  break;
               case R.id.emotionspage:
                   fragmentManager.beginTransaction()
                        .replace(R.id.content_frame
                        , new EmotionsFragment())
                        .commit();
                  break;
              case R.id.basicneedspage:
                  fragmentManager.beginTransaction()
                        .replace(R.id.content_frame
                        , new BasicneedsFragment())
                        .commit();
                  break;
              case R.id.exit:
                     //if you are in your activity close your app with
                      finish();
                      //or if you are insome fragment use
                      getActivity().finish();
                  break;
            }

            DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
            drawer.closeDrawer(GravityCompat.START);
            return true;
        }

我用switch case这样做，因为更清楚地阅读它，我的意见，但你当然可以用if else！

希望对您有所帮助！