Question

我通过数据绑定使用firebase回收器适配器填充firebase数据，并希望使用Picasso或Glide中的数据填充图像，但无法执行此操作。所以任何人都可以帮助我写什么以及在哪里写出毕加索或格莱德的代码。

public class ShopByCategoryFragment extends Fragment {

FirebaseRecyclerAdapter adapter;
Firebase mFirebaseRef = new Firebase("https://abc.firebaseio.com/").child("subCategories");

public ShopByCategoryFragment() {
    // Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.recycler_view, container, false);
    final RecyclerView recyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view);
    adapter = new FirebaseRecyclerAdapter<SubCategories, ViewHolder>(SubCategories.class, R.layout.fragment_shop_by_category,
            ViewHolder.class, mFirebaseRef) {
        @Override
        protected void populateViewHolder(ViewHolder viewHolder, SubCategories subCategories, int i) {


            FragmentShopByCategoryBinding binding = viewHolder.getBinding();
            binding.setSubCategories(subCategories);
        }
    };
    recyclerView.setAdapter(adapter);

    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 2));
    return rootView;
}

public static class ViewHolder extends RecyclerView.ViewHolder {

    public FragmentShopByCategoryBinding binding;

    public ViewHolder(View itemView) {
        super(itemView);
        binding = DataBindingUtil.bind(itemView);
    }
    public FragmentShopByCategoryBinding getBinding() {
        return binding;
    }
}
@Override
public void onDestroy() {
    super.onDestroy();
    adapter.cleanup();
}

}

<layout xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
    <variable
        name="SubCategories"
        type="com.abc.www.shopping.model.SubCategories"/>
</data>

<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="@dimen/tile_height"
            android:id="@+id/sub_category_image"
            android:scaleType="centerCrop"
            android:src="@{SubCategories.image}" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="@dimen/tile_height"
            android:text="@{SubCategories.title}"
            android:id="@+id/sub_category_title"
            android:padding="16dp"
            android:textColor="@color/colorSubCategoryTitle"
            android:layout_gravity="center"
            android:textAppearance="@android:style/TextAppearance.Material.Title"
            tools:targetApi="lollipop" />
    </FrameLayout>
</android.support.v7.widget.CardView>

public class SubCategories extends BaseObservable {

private String title;
private String image;

public SubCategories() {
    // empty constructor
}

public SubCategories(String title, String image) {
    this.title = title;
    this.image = image;

}

public String getTitle() {
    return title;
}

public String getImage() {
    return image;
}

}

Answer 1

我做了类似于你需要的东西。我将分享我的代码并做一些解释。

我有一个返回FirebaseRecyclerAdapter的类，如下所示：

public RecyclerView.Adapter postAdapter(String userKey, final Context context, MyClickListener clickListener) {
    Query userPostRef = postRef.child(userKey);
    myClickListener = clickListener;

    return new FirebaseRecyclerAdapter<PostModel, DataObjectHolder>(PostModel.class, R.layout.stream_layout, DataObjectHolder.class, userPostRef) {
        @Override
        public void populateViewHolder(final DataObjectHolder dataviewHolder, final PostModel postModel, int position) {
            StorageReference mStorageRef = FirebaseStorage.getInstance().getReference();
            mStorageRef.child("uploaded_captures/" + postModel.getImageFilename() + ".jpg").getDownloadUrl()
                    .addOnSuccessListener(new OnSuccessListener<Uri>() {
                        @Override
                        public void onSuccess(Uri uri) {
                            dataviewHolder.setImage(uri.toString(), context);
                            dataviewHolder.setComment(postModel.getPostComment());
                        }
                    }).addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception exception) {
                    Log.e("FirebaseRecyclerAdapter", exception.getMessage());
                }
            });
        }
    };
}

和一个ViewHolder，它将图像加载到布局使用的ImageView中：

private static class DataObjectHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    View mView;

    public DataObjectHolder(View itemView) {
        super(itemView);
        mView = itemView;
    }

    void setImage(final String imageURL, final Context context) {
        final ImageView postImage = (ImageView) mView.findViewById(R.id.imageView);
        if (BuildConfig.DEBUG) {
            Picasso.with(context).setIndicatorsEnabled(true);
        }
        Picasso.with(context)
                .load(imageURL)
                .networkPolicy(NetworkPolicy.OFFLINE)
                .placeholder(R.drawable.ic_menu_camera)
                .fit().centerCrop().into(postImage, new Callback() {
            @Override
            public void onSuccess() {
            }

            @Override
            public void onError() {
                Picasso.with(context)
                        .load(imageURL)
                        .placeholder(R.drawable.ic_menu_camera)
                        .fit().centerCrop().into(postImage);
            }
        });
    }

    void setComment(String text) {
        TextView comment = (TextView) mView.findViewById(R.id.comment);
        comment.setText(text);
    }

    @Override
    public void onClick(View v) {
        myClickListener.onItemClick(getAdapterPosition(), v);
    }
}

在Picasso上我使用NerworkPolicy.OFFLINE检查图像是否在磁盘缓存上，然后再尝试从网络上获取它。它并不完美，一旦ViewHolder被回收，我仍然会遇到一些图像延迟的问题，但我认为这是你继续下去的开始。

Answer 2

在我的ViewHolder中，我通过以下方式执行此操作：

Glide.with(context)
     .load(chat.getImageUrl())
     .into(imageView);

我还没有尝试使用data binding，但代码很简单。

通过数据绑定使用firebase回收器适配器填充图像

2 个答案: