Question

我已经创建了RecyclerView，并且有图像，并且使用按钮，我可以从RecyclerView中删除图像，但由于未从firebase 存储和数据库中删除该图像而再次出现。我还需要从存储和数据库中删除它。

我提供了大多数代码，因此您可以对其进行研究。

谢谢！

//imageAdapter.java Code

 public class ImageAdapter extends `enter code 
 RecyclerView.Adapter<ImageAdapter.ImageViewHolder> {
 private Context mContext;
 private List<Upload> mUploads;

 public ImageAdapter(Context context, List<Upload> uploads) {
    mContext = context;
    mUploads = uploads;
}

@Override
public ImageViewHolder onCreateViewHolder(ViewGroup parent, int viewType) 
{
    View v = LayoutInflater.from(mContext).inflate(R.layout.image_item, 
 parent, false);
    return new ImageViewHolder(v);
}

@Override
public void onBindViewHolder(final ImageViewHolder holder, final int 
position) {
    final Upload uploadCurrent = mUploads.get(position);
    holder.textViewName.setText(uploadCurrent.getName());
    Picasso.get()
            .load(uploadCurrent.getImageUrl())
            .placeholder(R.mipmap.ic_launcher)
            .into(holder.imageView);
}

@Override
public int getItemCount() {
    return mUploads.size();
}

public class ImageViewHolder extends RecyclerView.ViewHolder {
    public TextView textViewName;
    public ImageView imageView;

    public ImageViewHolder(View itemView) {
        super(itemView);

        textViewName = itemView.findViewById(R.id.text_view_name);
        imageView = itemView.findViewById(R.id.image_view_upload);
    }
}

}

//imageActivity.java code

public class ImagesActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private ImageAdapter mAdapter;

private ProgressBar mProgressCircle;

private FirebaseStorage mStorage;

private DatabaseReference mDatabaseRef;
private List<Upload> mUploads;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_images);
    mRecyclerView = findViewById(R.id.recycler_view);
    mRecyclerView.setHasFixedSize(true);
    mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

    mProgressCircle = findViewById(R.id.progress_circle);

    mUploads = new ArrayList<>();

    mStorage=FirebaseStorage.getInstance();//image delete

    mDatabaseRef = 
FirebaseDatabase.getInstance().getReference("uploads");

    mDatabaseRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            mUploads.clear();
            for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) 
{
                Upload upload = postSnapshot.getValue(Upload.class);
                upload.setKey(postSnapshot.getKey());
                mUploads.add(upload);
            }

            mAdapter = new ImageAdapter(ImagesActivity.this, mUploads);

            mRecyclerView.setAdapter(mAdapter);
            mProgressCircle.setVisibility(View.INVISIBLE);

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            Toast.makeText(ImagesActivity.this, 
databaseError.getMessage(), Toast.LENGTH_SHORT).show();
            mProgressCircle.setVisibility(View.INVISIBLE);
        }
    });

}
}

//Upload.java code
public class Upload {
private String mName;
private String mImageUrl;

private String mKey;

public Upload() {
    //empty constructor needed
}

public Upload(String name, String imageUrl) {
    if (name.trim().equals("")) {
        name = "No Name";
    }

    mName = name;
    mImageUrl = imageUrl;
}

public String getName() {
    return mName;
}

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

public String getImageUrl() {
    return mImageUrl;
}

public void setImageUrl(String imageUrl) {
    mImageUrl = imageUrl;
}
//image delete
@Exclude
public String getKey(){
    return mKey;
}
@Exclude
public void setKey(String key){
    mKey=key;
}//end image delete
}

//MainAcitivity.java code
public class MainActivity extends AppCompatActivity {

private static final int PICK_IMAGE_REQUEST = 1;

private Button mButtonChooseImage;
private Button mButtonUpload;
private TextView mTextViewShowUploads;
private EditText mEditTextFileName;
private ImageView mImageView;
private ProgressBar mProgressBar;
private Button deleteButton;

private Uri mImageUri;

private StorageReference mStorageRef;
private DatabaseReference mDatabaseRef;

private StorageTask mUploadTask;

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

    mButtonChooseImage = findViewById(R.id.button_choose_image);
    mButtonUpload = findViewById(R.id.button_upload);
    mTextViewShowUploads = findViewById(R.id.text_view_show_uploads);
    mEditTextFileName = findViewById(R.id.edit_text_file_name);
    mImageView = findViewById(R.id.image_view);
    mProgressBar = findViewById(R.id.progress_bar);
    deleteButton=findViewById(R.id.del_image);



    mStorageRef = FirebaseStorage.getInstance().getReference("uploads");
    mDatabaseRef = 
FirebaseDatabase.getInstance().getReference("uploads");

    mButtonChooseImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            openFileChooser();
        }
    });

    mButtonUpload.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mUploadTask != null && mUploadTask.isInProgress()) {
                Toast.makeText(MainActivity.this, "Upload in progress", 
Toast.LENGTH_SHORT).show();
            } else {
                uploadFile();
            }
        }
    });

    mTextViewShowUploads.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            openImagesActivity();
        }
    });
}

private void openFileChooser() {
    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, Intent 
data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK
            && data != null && data.getData() != null) {
        mImageUri = data.getData();

        Picasso.get().load(mImageUri).into(mImageView);
    }
}

private String getFileExtension(Uri uri) {
    ContentResolver cR = getContentResolver();
    MimeTypeMap mime = MimeTypeMap.getSingleton();
    return mime.getExtensionFromMimeType(cR.getType(uri));
}

private void uploadFile() {
    if (mImageUri != null) {
        StorageReference fileReference = 
mStorageRef.child(System.currentTimeMillis()
                + "." + getFileExtension(mImageUri));

        mUploadTask = fileReference.putFile(mImageUri)
                .addOnSuccessListener(new 
OnSuccessListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onSuccess(UploadTask.TaskSnapshot 
taskSnapshot) {
                        Handler handler = new Handler();
                        handler.postDelayed(new Runnable() {
                            @Override
                            public void run() {
                                mProgressBar.setProgress(0);
                            }
                        }, 500);
                        Task<Uri> urlTask = 
taskSnapshot.getStorage().getDownloadUrl();
                        while (!urlTask.isSuccessful());
                        Uri downloadUrl = urlTask.getResult();
                        Toast.makeText(MainActivity.this, "Upload 
successful", Toast.LENGTH_LONG).show();

注意：发布更多代码时遇到问题！！！

如何从recyclerview以及Firebase存储中删除特定图像？

0 个答案: