java - 从 firebase 的导航栏中加载个人资料图像和用户名

Question

image of database structure

code for database structure

我正在尝试检索用户在注册过程中在导航标题中保存的个人资料图像和用户名。这是我所做的事情。起初，我尝试获取字符串当前用户，但它显示了空指针异常，然后我尝试使用if语句并将子项从当前用户id更改为用户 ，它只解决了空指针问题，但没有从 firebase 检索数据。

MainActivity.java

   import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;

import de.hdodenhof.circleimageview.CircleImageView;

public class MainActivity extends AppCompatActivity {
    private NavigationView navigationView;
    private DrawerLayout drawerLayout;
    private RecyclerView postlist;
    private Toolbar mToolbar;
    private ActionBarDrawerToggle actionBarDrawerToggle;
    private FirebaseAuth mAuth;
    private FirebaseUser FirebaseUser;
    private DatabaseReference  UsersRef;
    private CircleImageView NavProfileImage;
    private TextView NavProfileUserName;
    String currentUserID;

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

        FirebaseUser mFirebaseUser = mAuth.getCurrentUser();
        if (mFirebaseUser != null) {
            currentUserID = mFirebaseUser.getUid();
        }
        mAuth = FirebaseAuth.getInstance();



        mToolbar =(Toolbar) findViewById(R.id.main_page_toolbar);
        setSupportActionBar(mToolbar);
        getSupportActionBar().setTitle("Home");

        drawerLayout = (DrawerLayout) findViewById(R.id.drawable_layout);
       actionBarDrawerToggle =  new ActionBarDrawerToggle(MainActivity.this,drawerLayout,R.string.drawer_open, R.string.drawer_close);
        navigationView = (NavigationView)findViewById(R.id.navigation_view);
       drawerLayout.addDrawerListener(actionBarDrawerToggle);
       actionBarDrawerToggle.syncState();
       getSupportActionBar().setDisplayHomeAsUpEnabled(true);


        View navView = navigationView.inflateHeaderView(R.layout.nav_header);
        NavProfileImage = (CircleImageView)navView.findViewById(R.id.nav_profile_image);
        NavProfileUserName = (TextView) navView.findViewById(R.id.nav_user_full_name);

        UsersRef = FirebaseDatabase.getInstance().getReference().child("Users");
        UsersRef.child(currentUserID).addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot)
            {
                if(dataSnapshot.exists())
                {   if (dataSnapshot.hasChild("fullname")){
                    String fullname = dataSnapshot.child("fullname").getValue().toString();
                    NavProfileUserName.setText(fullname);
                }if (dataSnapshot.hasChild("profileimages")) {
                    String image = dataSnapshot.child("profileimages").getValue().toString();
                    Picasso.with(MainActivity.this).load(image).placeholder(R.drawable.profile).into(NavProfileImage);

                }else {
                    Toast.makeText(MainActivity.this, "Profile name do not exists...", Toast.LENGTH_SHORT).show();
                }




                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

        navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item)
            { UserMenuSelector(item);

                return false;
            }
        });
    }

    @Override
    protected void onStart() {
        super.onStart();
        FirebaseUser currentUser = mAuth.getCurrentUser();
        if (currentUser == null)
        {
            sendUserToLoginActivity();
        }else{
            CheckUserExistance();
        }
    }

    private void CheckUserExistance()
    {
        final String current_user_id = mAuth.getCurrentUser().getUid();
          UsersRef.addValueEventListener(new ValueEventListener() {
              @Override
              public void onDataChange(DataSnapshot dataSnapshot) {
                  if (!dataSnapshot.hasChild(current_user_id)){
                      sendUserToSetupActivity();
                  }
              }

              @Override
              public void onCancelled(DatabaseError databaseError) {

              }
          });
    }

    private void sendUserToSetupActivity() {
        Intent setupIntent = new Intent(MainActivity.this, SetupActivity.class);
        setupIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(setupIntent);
        finish();

    }

    private void sendUserToLoginActivity()
    {
        Intent loginIntent = new Intent(MainActivity.this, LoginActivity.class);
         loginIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
         startActivity(loginIntent);
         finish();

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (actionBarDrawerToggle.onOptionsItemSelected(item))
        {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    private void UserMenuSelector(MenuItem item)
    {
        switch (item.getItemId())
        {
            case R.id.nav_home:
                Toast.makeText(this,"Home",Toast.LENGTH_SHORT).show();
                break;
            case R.id.nav_post:
                break;
            case R.id.nav_Profile:
                Toast.makeText(this,"profile",Toast.LENGTH_SHORT).show();
                break;
            case R.id.nav_find_friends:
                Toast.makeText(this,"frns",Toast.LENGTH_SHORT).show();
                break;
            case R.id.nav_logout:
                mAuth.signOut();
                sendUserToLoginActivity();
                break;
        }
    }
}

Answer 1

我使用 glide 从 firebase 加载图像。它会是这样的:

import com.bumptech.glide.Glide;

UserModel userModel = new UserModel;

Glide.with(YourActivity.this)
  .load(userModel.getUser_image())
  .into(user_image);

有关更多信息，请查看 github repository .