Question

我想从FirebaseStorageReference下载所有图像，并将其保存在arraylist中。当我在addOnSuccessListener之外使用位图时，请赋予位图null值。如何在arraylist中使用此位图。

       for (int i=0;i<cimage.size();i++) {


                StorageReference fileRef = FirebaseStorage.getInstance().getReferenceFromUrl(lang.cimage.get(i));
             // https://firebasestorage.googleapis.com/v0/b/app-5dc4e.appspot.com/o/color%2Fblackcar.png?alt=media&token=b1c5c0ec-e640-43c5-bd57-5112c106df94
if (fileRef != null) {

        final long ONE_MEGABYTE = 1024 * 1024;
        fileRef.getBytes(ONE_MEGABYTE).addOnSuccessListener(new OnSuccessListener<byte[]>() {
            @Override
            public void onSuccess(byte[] bytes) {

                Bitmap bmp = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                bmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
                byte[] byteArray = stream.toByteArray();
                intent.putExtra("bitmap", byteArray);
                startActivity(intent);


            }


        }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception exception) {
                //              progressDialog.dismiss();
                Toast.makeText(partques.this, exception.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
    } else {
        Toast.makeText(partques.this, "Upload file before downloading", Toast.LENGTH_LONG).show();
    }}
     byte[] byteArray = getIntent().getByteArrayExtra("bitmap");
    Log.e("Tag", "bitbyte "+byteArray); // byteArray show null
    Bitmap bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);

Answer 1

    private void uploadImage() {

      if(filePath != null)
      {
        final ProgressDialog progressDialog = new ProgressDialog(this);
        progressDialog.setTitle("Uploading...");
        progressDialog.show();

        StorageReference ref = storageReference.child("images/"+ UUID.randomUUID().toString());
        ref.putFile(filePath)
                .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                  @Override
                  public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                    progressDialog.dismiss();
                    Toast.makeText(MainActivity.this, "Uploaded", Toast.LENGTH_SHORT).show();

Picasso.get().load(taskSnapshot.getUri()).into(imageView);
                  }
                })
                .addOnFailureListener(new OnFailureListener() {
                  @Override
                  public void onFailure(@NonNull Exception e) {
                    progressDialog.dismiss();
                    Toast.makeText(MainActivity.this, "Failed "+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 "+(int)progress+"%");
                  }
                });
      }
    }

Answer 2

尝试一下：

 File filename = new File(Environment.getExternalStorageDirectory().getPath(), "myFile.jpeg");
            try (FileOutputStream out = new FileOutputStream(filename)) {
                bmp.compress(Bitmap.CompressFormat.PNG, 100, out); // bmp is your Bitmap instance
                // PNG is a lossless format, the compression factor (100) is ignored
            } catch (IOException e) {
                e.printStackTrace();
            }

将FirebaseStorageReference图像作为位图下载，并保存在Android的Arraylist中

2 个答案: