Question

我使用设计支持库创建了一个Navigation抽屉。当我打开导航抽屉并单击志愿者菜单项时，请参阅图像

enter image description here

我想要志愿者屏幕的内容，下面有三个标签，但仍然可以访问显示的导航栏。我尝试过实现该代码，但应用程序崩溃了

我尝试使用此示例https://guides.codepath.com/android/Fragment-Navigation-Drawer。但是具有

的Activity

我附上了主要活动的代码：

public class MainActivity extends AppCompatActivity {

    private DrawerLayout mDrawerLayout;

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        final ActionBar ab = getSupportActionBar();
        ab.setHomeAsUpIndicator(R.drawable.ic_menu);
        ab.setDisplayHomeAsUpEnabled(true);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        if (navigationView != null) {
            setupDrawerContent(navigationView);
        }

    }

    private void setupDrawerContent(NavigationView navigationView) {
        navigationView.setNavigationItemSelectedListener(
                new NavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(MenuItem menuItem) {
                        selectDrawerItem(menuItem);
                        return true;
                    }
                });

    }

    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_geotag:

                fragmentClass = (Fragment_GeoTag.class);

                break;

            case R.id.nav_footprint:

                fragmentClass = Fragment_Footprint.class;

                break;

            case R.id.nav_education:

                fragmentClass = Fragment_Education.class;

                break;
            case R.id.nav_rssfeeds:
                fragmentClass = SimpleRSSReaderActivity.class;
                break;

            default:

                fragmentClass = HomeActivity.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());
        mDrawerLayout.closeDrawers();


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.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.
        switch (item.getItemId()) {
            case android.R.id.home:
                mDrawerLayout.openDrawer(GravityCompat.START);
                return true;
        }
        ;

        //noinspection SimplifiableIfStatement
//        if (id == R.id.action_settings) {
//            return true;
//        }

        return super.onOptionsItemSelected(item);
    }

    public void onDrawerItemSelected(View view, int position) {
        displayView(position);
    }

    private void displayView(int position) {

    }

}

志愿者片段

import android.app.Activity;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.GravityCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by s210121629 on 2015-07-01.
 */
public class Fragment_Volunteer extends AppCompatActivity{
    private DrawerLayout mDrawerLayout;

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

       final ActionBar ab = getSupportActionBar();
        ab.setHomeAsUpIndicator(R.drawable.ic_menu);
       ab.setDisplayHomeAsUpEnabled(true);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        if (navigationView != null) {
            setupDrawerContent(navigationView);
        }

        ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
        if (viewPager != null) {
            setupViewPager(viewPager);
        }

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Here's a Snackbar", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                mDrawerLayout.openDrawer(GravityCompat.START);
                return true;
        }
        return super.onOptionsItemSelected(item);
    }

    private void setupViewPager(ViewPager viewPager) {
        Adapter adapter = new Adapter(getSupportFragmentManager());
        adapter.addFragment(new PersonalinfoFragment(),"Personal Info");
        adapter.addFragment(new MedicalinfoFragment(), "Medical Info");
        adapter.addFragment(new ContactinfoFragment(), "Contact Info");
        viewPager.setAdapter(adapter);
    }

    private void setupDrawerContent(NavigationView navigationView) {
        navigationView.setNavigationItemSelectedListener(
                new NavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(MenuItem menuItem) {
                        menuItem.setChecked(true);
                        mDrawerLayout.closeDrawers();
                        return true;
                    }
                });
    }

    static class Adapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragments = new ArrayList<>();
        private final List<String> mFragmentTitles = new ArrayList<>();

        public Adapter(FragmentManager fm) {
            super(fm);
        }

        public void addFragment(Fragment fragment, String title) {
            mFragments.add(fragment);
            mFragmentTitles.add(title);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragments.get(position);
        }

        @Override
        public int getCount() {
            return mFragments.size();
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitles.get(position);
        }
    }
}

activity_main布局

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <!--<include layout="@layout/include_list_viewpager"/>-->


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <include
            layout="@layout/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <FrameLayout

            android:id="@+id/flContent"
            android:layout_width="match_parent"
            android:layout_height="match_parent">


        </FrameLayout>

    </LinearLayout>

    <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"
        app:menu="@menu/drawer_view" />

</android.support.v4.widget.DrawerLayout>

个人资料活动布局

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/sin"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:fitsSystemWindows="true">

    <include layout="@layout/profile_listview_pager"/>

    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_height="match_parent"
        android:layout_width="wrap_content"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/drawer_view"/>

</android.support.v4.widget.DrawerLayout>

logcat的：

Process: com.example.s210121629.eama, PID: 3185
java.lang.NullPointerException
        at android.support.v4.app.BackStackRecord.doAddOp(BackStackRecord.java:417)
        at android.support.v4.app.BackStackRecord.replace(BackStackRecord.java:452)
        at android.support.v4.app.BackStackRecord.replace(BackStackRecord.java:444)
        at com.example.s210121629.eama.MainActivity.selectDrawerItem(MainActivity.java:108)
        at com.example.s210121629.eama.MainActivity$1.onNavigationItemSelected(MainActivity.java:48)
        at android.support.design.widget.NavigationView$1.onMenuItemSelected(NavigationView.java:136)
        at android.support.v7.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:811)
        at android.support.v7.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:153)
        at android.support.v7.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:958)
        at android.support.design.internal.NavigationMenuPresenter.onItemClick(NavigationMenuPresenter.java:179)
        at android.widget.AdapterView.performItemClick(AdapterView.java:308)
        at android.widget.AbsListView.performItemClick(AbsListView.java:1524)
        at android.widget.AbsListView$PerformClick.run(AbsListView.java:3531)
        at android.widget.AbsListView$3.run(AbsListView.java:4898)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5586)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
        at dalvik.system.NativeStart.main(Native Method)

Answer 1

志愿者片段不是片段，因为它扩展了AppCompatActivity。它应该扩展Fragment。

在导航抽屉中单击监听器，您应该执行以下操作：

getSupportFragmentManager().beginTransaction().replace(R.id.frame_container, new Fragment_Volunteer()).commit();

Answer 2

你应该只使用Activity：“MainActivity” 当你在项目菜单上显示“Fragment_Volunteer”放在开关盒内时：

getSupportFragmentManager()
.beginTransaction()
.replace(R.id.frame_container, new Fragment_Volunteer())
.commit();

使用下一个代码：

Fragment_Volunteer extends Fragment

最后Fragment不使用：

protected void onCreate(Bundle savedInstanceState) {}

代码正确如下：

public class Fragment_Volunteer extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      View view = inflater.inflate(R.layout.activity_profile, container, false);
      return view;
    }
}

我希望能帮助，抱歉我的英语不好

在仍然可以访问导航抽屉的情况下启动新活动

2 个答案: