Question

我正在创建一个应用程序，其中只有一个用户（管理员）可以在应用程序中发布，而其他用户只能阅读新闻。我已禁止在Firebase中为用户编写内容，但我只想向管理员用户显示添加按钮

这是main_menu xml代码：

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.ekene.blogzone.MainActivity">
<item
    android:id="@+id/action_shto"
    android:icon="@drawable/shto"
    app:showAsAction="always"
    android:title="Shto"
    />
<item
    android:id="@+id/dil"
    android:icon="@drawable/dil"
    app:showAsAction="always" />

这是MainActivity代码：

public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private DatabaseReference mDatabase;
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;
private LinearLayoutManager layoutManager;


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

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setBackgroundDrawable(new 
    ColorDrawable(getResources().getColor(R.color.white)));


    //Shfaqë Welcome Screen vetëm pas instalimit të aplikacionit
    Thread t = new Thread(new Runnable() {
        @Override
        public void run() {
            SharedPreferences getPrefs = PreferenceManager
                    .getDefaultSharedPreferences(getBaseContext());
            boolean isFirstStart = getPrefs.getBoolean("firstStart", true);

            if (isFirstStart) {
                final Intent i = new Intent(MainActivity.this, 
            Welcome.class);

                runOnUiThread(new Runnable() {
                    @Override public void run() {
                        startActivity(i);
                    }
                });

                SharedPreferences.Editor e = getPrefs.edit();
                e.putBoolean("firstStart", false);
                e.apply();
                finish();
            }
        }
    });
    t.start();



    recyclerView = (RecyclerView) findViewById(R.id.rcView);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setHasFixedSize(true);
    recyclerView.setNestedScrollingEnabled(false);

    layoutManager = new LinearLayoutManager(MainActivity.this, 
    RecyclerView.HORIZONTAL, false);
    layoutManager.setReverseLayout(true);
    layoutManager.setStackFromEnd(true);


    mDatabase = 
    FirebaseDatabase.getInstance().getReference().child("Tech_News");
    mAuth = FirebaseAuth.getInstance();
    mAuthListener = new FirebaseAuth.AuthStateListener()
    {
        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth)
        {
            if (mAuth.getCurrentUser()==null)
            {
                Intent kyqjaIntent = new Intent(MainActivity.this, 
       KyqjaActivity.class);
                kyqjaIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
                startActivity(kyqjaIntent);
            }
        }
    };
}


@Override
protected void onStart() {
    super.onStart();
    mAuth.addAuthStateListener(mAuthListener);
    FirebaseRecyclerAdapter<TechNews, TechNewsViewHolder> 
firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<TechNews, 
TechNewsViewHolder>(
            TechNews.class,
            R.layout.card_items,
            TechNewsViewHolder.class,
            mDatabase
    ) {


        @Override
        protected void populateViewHolder(final TechNewsViewHolder 
viewHolder, final TechNews model, int position) {

            final String post_key = getRef(position).getKey().toString();

                mDatabase.child(post_key).addValueEventListener(new 
ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {


                        String titulli_postit = (String) 
dataSnapshot.child("Titulli").getValue();
                        String pershkrimi_postit = (String) 
dataSnapshot.child("Përshkrimi").getValue();
                        String fotografia_postit = (String) 
dataSnapshot.child("fotografiaUrl").getValue();
                        String emri = (String) 
dataSnapshot.child("Përdoruesi").getValue();

                        viewHolder.setTitulli(titulli_postit);
                        viewHolder.setPershkrimi(pershkrimi_postit);
                        viewHolder.setFotoUrl(getApplicationContext(), 
 fotografia_postit);
                        viewHolder.setEmri(emri);



                        viewHolder.mView.setOnClickListener(new 
View.OnClickListener() {
                            @Override
                            public void onClick(View view)
                            {
                                Intent postihapurActivity = new 
Intent(MainActivity.this, PostiHapurActivity.class);
                                postihapurActivity.putExtra("PostiID", 
post_key);
                                startActivity(postihapurActivity);
                            }
                        });

                    }

                    @Override
                    public void onCancelled(DatabaseError databaseError) {

                    }

            });
        }
    };
    recyclerView.setLayoutManager(layoutManager);
    recyclerView.setAdapter(firebaseRecyclerAdapter);
}



public static class TechNewsViewHolder extends RecyclerView.ViewHolder
{
    View mView;
    public TechNewsViewHolder(View itemView)
    {
        super(itemView);
        mView = itemView;
    }

    public void setTitulli(String titulli)
    {
        TextView titulli_postit = 
mView.findViewById(R.id.posti_titulli_txtview);
        titulli_postit.setText(titulli);
    }

    public void setPershkrimi(String pershkrimi)
    {
        TextView pershkrimi_postit = 
mView.findViewById(R.id.posti_pershkrimi_txtview);
        pershkrimi_postit.setText(pershkrimi);
    }

    public void setFotoUrl (Context ctx, String fotoUrl)
    {
        ImageView foto_posti = mView.findViewById(R.id.posti_fotoja);
        Picasso.with(ctx).load(fotoUrl).into(foto_posti);
    }
    public void setEmri (String emri)
    {
        TextView emri_posti = mView.findViewById(R.id.posti_emri);
        emri_posti.setText(emri);
    }
}



@Override
public boolean onCreateOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}



@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();


    if (id == R.id.action_shto)
    {
        startActivity(new Intent(MainActivity.this, PostiActivity.class));
    }
    else if (id == R.id.dil)
    {
        mAuth.signOut();
        Intent dilIntent = new Intent(MainActivity.this, KyqjaActivity.class);
        dilIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(dilIntent);
    }

    return super.onOptionsItemSelected(item);
}

}

Answer 1

您可以在setVisibile(true)方法中使用onCreateOptionsMenu方法隐藏特殊操作，如下所示：

MenuItem addAction = menu.findItem(R.id.add_action).setVisible(true);

Answer 2

我建议您创建一个保存用户类型的变量：例如，在注册期间，如果用户是admin，则将用户类型变量存储为“ Admin”，然后检查用户类型是否等于“ Admin” ”显示添加按钮，否则不要

Android显示菜单项仅适用于用户

2 个答案: