android - Picasso 未从 Firebase 数据库的 URL 加载图像

Question

Firebase image

Model class

 public class Category
{
    private String Name;
    private String Image;

    public Category(String name, String image) {
        Name = name;
        Image = image;
    }

    public Category() {
    }

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        Name = name;
    }

    public String getImage() {
        return Image;
    }

    public void setImage(String image) {
        Image = image;
    }
}

Activity class

 public class Home extends AppCompatActivity
            implements NavigationView.OnNavigationItemSelectedListener {

        RecyclerView recyclerView;
        RecyclerView.LayoutManager layoutManager;

        FirebaseDatabase database;
        DatabaseReference reference;
        FirebaseStorage storage;
        StorageReference storageReference;

        //Add new menu
        MaterialEditText edtTxtName;
        Button selectImage;
        Button uploadImage;

        //Adding new category
        Category newCategory;
        Uri savedImageUri;
        private final int PICK_IMAGE_REQUEST=71;
        MaterialEditText edtTxtNewCategoryName;

        FloatingActionButton fab;

        FirebaseRecyclerAdapter<Category,MenuViewHolder> recyclerAdapter;


        TextView userName;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_home);
            edtTxtNewCategoryName=findViewById(R.id.edt_txt_new_item_name);
            Toolbar toolbar = findViewById(R.id.toolbar);
            toolbar.setTitle("Menu Mangement");
            setSupportActionBar(toolbar);
            fab =findViewById(R.id.fab);


            //Firebase init
            database=FirebaseDatabase.getInstance();
            reference=database.getReference("Category");
            storage=FirebaseStorage.getInstance();
            storageReference=storage.getReference();

            fab.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    showDailog();
                }
            });


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

            //Setting header name
          /*  View view=navigationView.getHeaderView(0);
            userName = view.findViewById(R.id.username);
            userName.setText(Common.currentUser.getName());*/
            //View init
            recyclerView=findViewById(R.id.recycler_menu);
            layoutManager=new LinearLayoutManager(this);
            recyclerView.setLayoutManager(layoutManager);

            loadMenu();
        }

        private void selectImage() {
            Intent intent=new Intent();
            intent.setType("image/*");
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(intent,PICK_IMAGE_REQUEST);

        }

        @Override
        protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
            if(requestCode==PICK_IMAGE_REQUEST && resultCode==Activity.RESULT_OK
            && data!=null && data.getData()!=null)
            {
                savedImageUri=data.getData();//getting uri
                selectImage.setText("Image Selected !");
            }
        }

        private void uploadImage() {
            final ProgressDialog progressDialog=new ProgressDialog(this);
            progressDialog.setMessage("Uploading Image");
            progressDialog.show();

            String image= UUID.randomUUID().toString();
            final StorageReference imageFolder=storageReference.child("images/"+image);
            imageFolder.putFile(savedImageUri).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                    progressDialog.dismiss();
                    Toast.makeText(Home.this, "Uploaded", Toast.LENGTH_SHORT).show();
                    imageFolder.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>()
                    {
                        @Override
                        public void onSuccess(Uri uri)
                        {
                            newCategory=new Category(edtTxtName.getText().toString(),uri.toString());
                            Toast.makeText(Home.this, ""+uri.toString(), Toast.LENGTH_SHORT).show();

                        }
                    });

                }
            }).addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception e) {
                    progressDialog.dismiss();
                    Toast.makeText(Home.this, ""+e.getMessage(), Toast.LENGTH_SHORT).show();
                }
            }).addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
                   double progress=(100.0 * taskSnapshot.getBytesTransferred()
                   / taskSnapshot.getTotalByteCount());
                   progressDialog.setMessage("Uploaded "+progress+" %");

                }
            });
        }

        private void showDailog() {
            final AlertDialog.Builder alertDailog=new AlertDialog.Builder(this);
            alertDailog.setTitle("Add new Category");
            alertDailog.setMessage("Please fill all the fields");

            LayoutInflater inflater=this.getLayoutInflater();
            View view=inflater.inflate(R.layout.add_new_menu_layout,null);
            edtTxtName=view.findViewById(R.id.edt_txt_new_item_name);

            alertDailog.setView(view);
            alertDailog.setIcon(R.drawable.ic_shopping_cart_black_24dp);

            alertDailog.setPositiveButton("Add", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    if(newCategory!=null){
                        reference.push().setValue(newCategory);

                    }
                }
            });

            alertDailog.setNegativeButton("No", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });
            alertDailog.setNeutralButton("Cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });
            alertDailog.show();

        }

        private void loadMenu()
        {
            recyclerAdapter=new FirebaseRecyclerAdapter<Category, MenuViewHolder>(
                    Category.class,R.layout.menu_layout,
                    MenuViewHolder.class,reference) {
                @Override
                protected void populateViewHolder(MenuViewHolder viewHolder, final Category model, int position)
                {
                    viewHolder.menuName.setText(model.getName());
                    Picasso.get().load(model.getImage()).into(viewHolder.imageView);

                    viewHolder.setItemClickListner(new ItemClickListner() {
                        @Override
                        public void onClick(View view, int position, boolean isLongClick) {
                            //Getting menuId
                        Intent intent=new Intent(Home.this,FoodList.class);
                        intent.putExtra("CategoryId",recyclerAdapter.getRef(position).getKey());
                        startActivity(intent);
                        }
                    });
                }
            };

            recyclerAdapter.notifyDataSetChanged();//notifiy us if data has been changed.
            recyclerView.setAdapter(recyclerAdapter);
        }

在 Activity 类中，实现了 firebase 适配器。通过 firebase 数据库的引用，图像正在加载只有 id“-LO061DOhjG2hVZlqY79”，但没有加载像“01”“02”这样的 id

适配器加载图像非常慢 Output of this code

帮助将不胜感激

Answer 1

因为您使用的是私有(private)字段和公共(public) getter 和 setter，所以您的字段在 Category 类中的名称并不重要。如果您想在类中使用与数据库中不同的名称，您可以使用名为 PropertyName 的注释。在 setter/getter 前面。

images are loading with the only id "-LO061DOhjG2hVZlqY79" but with id's like '01' '02' are not loading

正如我在您的 screenshot 中看到的那样，名称为“Finger Foods”的第一个元素“01”的图像在 UI 中正确显示。因此，无论子项的 key 是否类似于 01、02 或 -LO061DOhjG2hVZlqY79，都应显示数据。事实上，它显示了，显示了下一个项目的名称，“西式汤”，所以很可能是您的 URL 有问题。因此，请确保该 URL 确实存在并且包含有效图像。