Question

我有一个应用程序，用户拍照并将图片加载到ImageView中，然后保存在FirebaseStorage中。当互联网速度很慢时，我在使用Firebase（使用Picasso）获取图像时遇到问题。如何在转换为字节数组并保存到Firebase之前减小位图的大小？

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == getActivity().RESULT_OK) {
        Bundle extras = data.getExtras();
        Bitmap imageBitmap = (Bitmap) extras.get("data");
        imageView.setImageDrawable(makeImageRounded(imageBitmap));
        detailViewModel.uploadPhotoToFirebase(imageBitmap); 
    }
}

Answer 1

在App中设置权限

select (case when genres like 'Fiction%' then 'Fiction' when genres like 'Nonfiction%' then 'Nonfiction' when genres like 'Historical%' then 'Historical' else 'Other' end) as genre, count(*) from books group by (case when genres like 'Fiction%' then 'Fiction' when genres like 'Nonfiction%' then 'Nonfiction' when genres like 'Historical%' then 'Historical' else 'Other' end);

声明imageView和uri

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

Firebase存储声明

private Uri filePath;
private final int PICK_IMAGE_REQUEST = 71;

在onCreate中启动

storage = FirebaseStorage.getInstance（）; storageReference = storage.getReference（）;

按下按钮

FirebaseStorage storage;
StorageReference storageReference;

onActivityResult您将获得文件路径

 private void chooseImage() {
  Intent intent = new Intent();
  intent.setType("image/*");
  intent.setAction(Intent.ACTION_GET_CONTENT);
  startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST);
}

将图片上传到firebase

@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 )
  {
    filePath = data.getData();
    try {
      Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
      imageView.setImageBitmap(bitmap);
    }
    catch (IOException e)
    {
      e.printStackTrace();
    }
  }
}

减少特定位图的大小以保存在firebase上

private void uploadImage() {

        if(filePath != null)
        {
            StorageReference ref = storageReference.child("images/"+ UUID.randomUUID().toString());
            ref.putFile(filePath)
                    .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {

                            Toast.makeText(this, "Uploaded", Toast.LENGTH_SHORT).show();
                        }
                    })
                    .addOnFailureListener(new OnFailureListener() {
                        @Override
                        public void onFailure(@NonNull Exception e) {


                        }
                    })
                    .addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
                        }
                    });
        }
    }

调用方法 - public Bitmap getResizedBitmap(Bitmap image, int maxSize) { int width = image.getWidth(); int height = image.getHeight(); float bitmapRatio = (float)width / (float) height; if (bitmapRatio > 1) { width = maxSize; height = (int) (width / bitmapRatio); } else { height = maxSize; width = (int) (height * bitmapRatio); } return Bitmap.createScaledBitmap(image, width, height, true); }

缩小Android中的位图

1 个答案: