一键关闭所有片段，然后返回活动

Question

我在导航抽屉活动上调用片段。毕竟，我想关闭所有片段，并在单击浮动按钮时查看我的导航抽屉活动的内容页面。什么是代码？

        import android.content.Intent;
        import android.content.SharedPreferences;
        import android.os.Bundle;
        import android.support.design.widget.FloatingActionButton;
        import android.support.design.widget.Snackbar;
        import android.support.v4.app.Fragment;
        import android.support.v4.app.FragmentManager;
        import android.support.v4.content.ContextCompat;
        import android.view.View;
        import android.support.design.widget.NavigationView;
        import android.support.v4.view.GravityCompat;
        import android.support.v4.widget.DrawerLayout;
        import android.support.v7.app.ActionBarDrawerToggle;
        import android.support.v7.app.AppCompatActivity;
        import android.support.v7.widget.Toolbar;
        import android.view.Menu;
        import android.view.MenuItem;
        import android.view.Window;
        import android.view.WindowManager;
        import android.widget.ArrayAdapter;
        import android.widget.ImageButton;
        import android.widget.ImageView;
        import android.widget.ListView;
        import android.widget.TextView;
public class Manager extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener,View.OnClickListener {
    Data dat=new Data();
    private ImageView imageView;
    private ImageButton logout,viewlibrary;
    TextView headerTitle;
    FragmentManager fragmentManager;
    String manager="";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_manager);
        headerTitle=(TextView)findViewById(R.id.headertitle);
        headerTitle.setText("Manager's Panel");
        TextView tv=(TextView)findViewById(R.id.usrmsgman);
        tv.setText("USER : "+dat.getUser());
        logout=(ImageButton)findViewById(R.id.logoutbut);
        viewlibrary=(ImageButton)findViewById(R.id.libview);
/*
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        */
        ListView lv=(ListView)findViewById(R.id.listView);
        Downloader d=new Downloader(this,dat.getHost()+"managerhome.php",lv);
        d.execute();
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                /*
---------------------------------------------------------------------------
---------------------------------------------------------------------------
---------------------------------------------------------------------------
What to do here?
---------------------------------------------------------------------------
---------------------------------------------------------------------------
---------------------------------------------------------------------------

*/
            });
            logout.setOnClickListener(this);
            viewlibrary.setOnClickListener(this);
            NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
            navigationView.setNavigationItemSelectedListener(this);
        }
        @Override
        public void onClick(View v) {
            switch (v.getId())
            {
                case R.id.logoutbut :
                    SharedPreferences sp=getSharedPreferences("Login", 0);
                    SharedPreferences.Editor Ed=sp.edit();
                    Ed.putString("Unm",null );
                    Ed.putString("Psw",null);
                    Ed.putString("app",null);
                    Ed.commit();
                    this.finish();
                    startActivity(new Intent(Manager.this,Login.class));
                    break;
                case R.id.libview :
                    startActivity(new Intent(this,ViewLibrary.class));
                    break;
            }
        }
        @Override
        public void onBackPressed() {
            DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
            if (drawer.isDrawerOpen(GravityCompat.START)) {
                drawer.closeDrawer(GravityCompat.START);
            } else {
                super.onBackPressed();
            }
        }
    public void removeFragment(Fragment fragment){
        android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
        android.support.v4.app.FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.remove(fragment);
        fragmentTransaction.commit();
    }
    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        if (id == R.id.nav_issue) {
            IssueFragment issueFragment=new IssueFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment,issueFragment).commit();
        } else if (id == R.id.nav_reissue) {
            RIssueFragment rissueFragment = new RIssueFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment, rissueFragment).commit();
        } else if (id == R.id.nav_retbook) {
            ReturnFragment returnFragment= new ReturnFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment,returnFragment).commit();
        } else if (id == R.id.nav_search) {
            SearchFragment searchFragment= new SearchFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment,searchFragment).commit();
        } else if (id == R.id.nav_abtApp) {
            AbtAppFragment abtAppFragment=new AbtAppFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment,abtAppFragment).commit();
        } else if (id == R.id.nav_abtDev) {
            AbtDevFragment abtDevFragment= new AbtDevFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment,abtDevFragment).commit();
        } else if (id == R.id.nav_view_mem) {
            ViewMemberFragment viewMemberFragment= new ViewMemberFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment,viewMemberFragment).commit();
        } else if (id == R.id.nav_log) {
            LogFragment logFragment= new LogFragment();
            FragmentManager manager=getSupportFragmentManager();
            fragmentManager=manager;
            manager.beginTransaction().replace(R.id.reloutForFragment,logFragment).commit();
        }
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

我可以做

Intent intent = getIntent();
finish();
startActivity(intent);

，但我不想重新启动活动

Answer 1

为主布局创建片段，当您的活动开始时，将主片段添加到这样的活动中：

if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
            .replace(R.id.reloutForFragment, fragment)
            .commit();
}

单击"浮动动作"按钮时调用相同的代码。