Question

我正在使用recyclerview从firebase数据库中检索数据，该数据运行良好，但我已将默认布局管理器设置为线性，但我希望用户必须能够从listview切换到无法正常工作的gridview。当我点击gridview项目时它没有改变状态。它没有任何东西保持默认状态为linearlayout manager。

public class Welcome extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    FirebaseDatabase database;
    DatabaseReference category;
    TextView txtfullname;
    RecyclerView recycler_menu;
    RecyclerView.LayoutManager layoutManager;
    FirebaseRecyclerAdapter<Category,MenuViewHolder> adapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_welcome);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle("Menu");
        setSupportActionBar(toolbar);

        //init firebase
        database = FirebaseDatabase.getInstance();
        category=database.getReference("Category");



        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.addDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);


    //set name for user
    View headerView= navigationView.getHeaderView(0);
    txtfullname= headerView.findViewById(R.id.nav_view);
//    txtfullname.setText(Common.currentUser.getName());

    //Load menu using firebase ui to bind data from frebase to recyclerview

        recycler_menu =findViewById(R.id.recyclerview);
        recycler_menu.setHasFixedSize(true);
        layoutman();
        recycler_menu.setLayoutManager(layoutManager);

        loadMenu();

    }

    private void layoutman() {
        layoutManager=new LinearLayoutManager(this);

    }

    private void loadMenu() {
         adapter =new FirebaseRecyclerAdapter<Category, MenuViewHolder>(Category.class,R.layout.menu_item,MenuViewHolder.class,category) {
            @Override
            protected void populateViewHolder(MenuViewHolder viewHolder, Category model, int position) {
                viewHolder.txtMenuName.setText(model.getName());
                Picasso.with(getBaseContext()).load(model.getImage())
                        .into(viewHolder.imageView);
                final Category clickItem = model;
                viewHolder.setItemClickListener(new ItemClickListener() {
                    @Override
                    public void onClick(View view, int position, boolean isLongClick) {
                        Toast.makeText(Welcome.this,""+clickItem.getName(),Toast.LENGTH_SHORT).show();
                    }
                });
            }
        };
        recycler_menu.setAdapter(adapter);
        adapter.notifyDataSetChanged();
    }

    @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.welcome, 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;
        }
        if (id==R.id.list){
        layoutman();
        adapter.notifyDataSetChanged();

            return true;
        }
        if (id==R.id.grid){
            layoutManager=new GridLayoutManager(getApplicationContext(),2);
            adapter.notifyDataSetChanged();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

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

        } else if (id == R.id.nav_orders) {

        } else if (id == R.id.nav_log_out) {

        } else if (id == R.id.share) {

        }

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

Answer 1

你做得对，但需要再次在recyclerview上设置布局管理器，否则它将无法工作，之后只需调用notifydatasetchanged（）就可以了。

Answer 2

您必须在点击事件上更改布局管理器，例如，对于Listview数据，您的布局管理器应该是

compile 'com.android.support:recyclerview-v7:23.2.0'

网格视图布局管理器的代码

RecyclerView recyclerView = (RecyclerView)findViewById(R.id.card_recycler_view);
    recyclerView.setHasFixedSize(true);
    RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getApplicationContext(),2);
    recyclerView.setLayoutManager(layoutManager);

简单列表视图

  RecyclerView recyclerView = (RecyclerView)findViewById(R.id.card_recycler_view);
    recyclerView.setHasFixedSize(true);
    RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
    recyclerView.setLayoutManager(layoutManager);

然后你必须分别改变列表视图，我希望这会对你有帮助

使用Recyclerview将GridView切换到Listview，反之亦然

2 个答案: