android - 在 RecyclerView 中显示 firebase 存储图像

Question

您好，我之前问过一个关于使用 Firebase 数据库中的 Base64 显示图像的问题。建议使用 firebase 存储。我重新编写了我的代码，所有内容都按原样加载到 firebase 存储和数据库中。我遇到的问题是，当我保存数据时，没有任何内容填充到我的 recyclerview 中。一切都是空白。

如果您能为我提供任何帮助以使其正常工作，那就太好了。谢谢。

编辑:在我的 Activity 课上，我调用了一个按钮点击监听器来激活相机。拍照后，它会保存到 Firebase 存储中。然后我从 Storage 下载图像并将其显示在 recyclerview 中。我理解上传部分，但我很难理解下载和显示部分。谢谢。

viewholder:绑定(bind)方法

public void bind (ImageProgress progress){

    Glide.with(activity).load("").into(image);
 }
}

适配器

  @Override
public ProgressViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
    return new ProgressViewHolder(activity, activity.getLayoutInflater().inflate(R.layout.weight_progress_list, parent, false));

主要 Activity 类

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

    saveButton = (Button) findViewById(R.id.saveButton);
    progressStatusEditText = (EditText) findViewById(R.id.progressStatusEditText);
    progressList = (RecyclerView) findViewById(R.id.progressList);
    mImageButton = (ImageButton) findViewById(R.id.takePictureButton);
    capturedImage=(ImageView)findViewById(R.id.capturedImageView);

    LinearLayoutManager layoutManager = new LinearLayoutManager(this);
    progressList.setHasFixedSize(false);
    progressList.setLayoutManager(layoutManager);

    //take picture button
    mImageButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            openCamera();
        }
    });


    mDatabaseReference = database.getReference("Progress");

    saveButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            //get current user
            FirebaseUser user =FirebaseAuth.getInstance().getCurrentUser();
            String uid = user.getUid();
            ImageProgress progress = new ImageProgress(uid, progressStatusEditText.getText().toString());
            mDatabaseReference.push().setValue(progress);
            progressStatusEditText.setText("");
        }
    });
}

private void openCamera() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(intent, REQUEST_IMAGE_CAPTURE);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {

        Uri cameraImageURI = data.getData();
        //reference where images will be stored
        mStorageReference = storage.getReference("Progress Images");
        //reference to store file
        final StorageReference cameraImageRef = mStorageReference.child(cameraImageURI.getLastPathSegment());
        //upload to firebase storage
        cameraImageRef.putFile(cameraImageURI)
                .addOnSuccessListener(this, new OnSuccessListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                        Uri downloadUrl = taskSnapshot.getDownloadUrl();
                        progressStatusEditText.setText(downloadUrl.toString());
                    }
                });
}

Answer 1

我建议您在 RecyclerView.ViewHolder 上添加 setImage 方法，并将图像的 url 存储在您在 FirebaseRecyclerAdapter 中检索的对象中。

就我而言，我使用的是 Glide管理我的应用程序的图像:

我的 ViewHolder 示例:

public class UserListViewHolder extends RecyclerView.ViewHolder {
private final View mView;
private static final int POST_TEXT_MAX_LINES = 6;
private ImageView mIconView;
private TextView mAuthorView;
private UserClickListener mListener;

public UserListViewHolder(View itemView) {
    super(itemView);
    mView = itemView;
    mIconView = (ImageView) mView.findViewById(R.id.user_image_profile);
    mAuthorView = (TextView) mView.findViewById(R.id.user_text_profile);
    mView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mListener.onUserClick();
        }
    });
}

public void setIcon(String url) {
    GlideUtil.loadProfileIcon(url, mIconView);//       
}

public void setPostClickListener(UserClickListener listener) {
    mListener = listener;
}


public void setText(final String text) {
    if (text == null || text.isEmpty()) {
        mAuthorView.setVisibility(View.GONE);
        return;
    } else {
        mAuthorView.setVisibility(View.VISIBLE);
        mAuthorView.setText(text);
        mAuthorView.setMaxLines(POST_TEXT_MAX_LINES);
    }
}

public interface UserClickListener {
    void onUserClick();
}
}

这是我的数据库调用:

 private FirebaseRecyclerAdapter<Person, UserListViewHolder> getFirebaseRecyclerAdapter(Query query) {
    return new FirebaseRecyclerAdapter<Person, UserListViewHolder>(
            Person.class, R.layout.user_row_item, UserListViewHolder.class, query) {

        @Override
        protected void populateViewHolder(UserListViewHolder viewHolder, Person model, int position) {
            setupUser(viewHolder, model, position, null);
        }

    };
}

private void setupUser(final UserListViewHolder UserViewHolder, final Person user, final int position, final String inPostKey) {
    final String postKey;
    if (mAdapter instanceof FirebaseRecyclerAdapter) {
        postKey = ((FirebaseRecyclerAdapter) mAdapter).getRef(position).getKey();
    } else {
        postKey = inPostKey;
    }
    FirebaseUtil.getUsersRef().child(postKey).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(final DataSnapshot dataSnapshot) {
            UserViewHolder.setPostClickListener(new UserListViewHolder.UserClickListener() {
                @Override
                public void onUserClick() {
                    mGroup.addUserToGroup(dataSnapshot.getKey());
                }
            });
            UserViewHolder.setIcon(dataSnapshot.child("photoUrl").getValue(String.class));
            UserViewHolder.setText(dataSnapshot.child("displayName").getValue(String.class));

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
}

您只需按照从 Firebase 检索数据时设置其他值的方式设置图像，但在将图像上传到云端后使用您已经为该图像生成的新 URL。

也许你可以找到另一种方法来设置 url，但我建议你将它保留为自定义对象中的另一个参数，如果你想多次检索该数据即使你没有上传图像也是动态的.