在 Android Studio 中单击 Drawer 项无法加载新片段

Question

我已经实现了以下代码，但是当我运行应用程序并单击抽屉中的一个项目时，什么也没发生。我想这是与侦听器有关的问题，但我不知道如何解决它。或者可能是其他问题！

一旦我点击一个项目，唯一发生的事情就是 logcat 中的以下两行：

01-12 03:14:26.606 1565-1565/? I/LatinIME: Starting input. Cursor position = -1,-1
01-12 03:14:29.601 1565-1565/? I/LatinIME: Starting input. Cursor position = 0,0

代码如下：

public class Welcome extends AppCompatActivity {
    private DrawerLayout mDrawer,dlDrawer;
    private NavigationView nvDrawer;
    private ActionBarDrawerToggle drawerToggle;

    private Toolbar toolbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.welcome);

        // Set a Toolbar to replace the ActionBar.
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        // Find our drawer view
        dlDrawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawerToggle = setupDrawerToggle();

        // Tie DrawerLayout events to the ActionBarToggle
        dlDrawer.setDrawerListener(drawerToggle);

       nvDrawer = (NavigationView) findViewById(R.id.nvView);
        // Setup drawer view
        setupDrawerContent(nvDrawer);

        FragmentTransaction tx = getSupportFragmentManager().beginTransaction();
        tx.replace(R.id.drawer_layout, new EditPersonal());
        tx.commit();
    }

    private void setupDrawerContent(NavigationView navigationView) {
        navigationView.setNavigationItemSelectedListener(
                new NavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(MenuItem menuItem) {
                        selectDrawerItem(menuItem);
                        return true;
                    }
                });
    }
    private ActionBarDrawerToggle setupDrawerToggle() {
        return new ActionBarDrawerToggle(this, dlDrawer, toolbar, R.string.drawer_open, R.string.drawer_close);
    }

    public void selectDrawerItem(MenuItem menuItem) {
        // Create a new fragment and specify the planet to show based on
        // position
        Fragment fragment = null;

        Class fragmentClass;
        switch(menuItem.getItemId()) {
            case R.id.nav_first_fragment:
                fragmentClass = EditPersonal.class;
                break;
            case R.id.nav_second_fragment:
                fragmentClass = Chronogram.class;
                break;
            case R.id.nav_third_fragment:
                fragmentClass = BloodTest.class;
                break;
            case R.id.nav_forth_fragment:
                fragmentClass = GlucoseTest.class;
                break;
            case R.id.nav_fifth_fragment:
                fragmentClass = SendRecord.class;
                break;
            case R.id.nav_sixth_fragment:
                fragmentClass = ReviewLogin.class;
                break;
            case R.id.nav_seventh_fragment:
                fragmentClass = SignOut.class;
                break;
            default:
                fragmentClass = EditPersonal.class;
        }

        try {
            fragment = (Fragment) fragmentClass.newInstance();
        } catch (Exception e) {
            e.printStackTrace();
        }

        // Insert the fragment by replacing any existing fragment
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.flContent,fragment).commit();

        // Highlight the selected item, update the title, and close the drawer
        menuItem.setChecked(true);
        setTitle(menuItem.getTitle());
        mDrawer.closeDrawers();
    }
    // ...
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (drawerToggle.onOptionsItemSelected(item)) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    // Make sure this is the method with just `Bundle` as the signature
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        drawerToggle.syncState();
    }
    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Pass any configuration change to the drawer toggles
        drawerToggle.onConfigurationChanged(newConfig);
    }
}

应用屏幕截图：

Answer 1

在您的开关盒上，尝试以下操作：

FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();

case R.id.nav_first_fragment:

     EditPersonal editPersonal= new EditPersonal();
     fragmentTransaction.replace(R.id.flContent, editPersonal);
     fragmentTransaction.commit();
     break;

在其他情况下也这样做。

Answer 2

您是否尝试过将日志放入您的代码中以查看逻辑流向或无法流向的位置？

例如，在您的 switch 语句中，尝试查看 menuItem.getItemId() 是否确实与您的 case 语句匹配。看看您的听众是否真的是问题所在，或者它是否与案例不匹配，这将有所帮助。或者这可能是您的片段管理器的问题。

查看http://developer.android.com/reference/android/util/Log.html。您应该能够在 logcat 中看到日志。祝你好运！

Answer 3

基本上我已经使用 Android Studio 本身的 Activity（导航抽屉活动）更改了代码。所以这里是代码：

    public class Welcome extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        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.drawer_open, R.string.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.review_login_listview, 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.menu_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();
        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();

        if (id == R.id.nav_first_fragment) {
            // Handle the camera action
        }
        else {

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