在android中显示大图像但共享较小的图像

Question

I am making an Android application, which shares images via social media. The images are in a grid layout , so when a user presses an image it opens another activity which will show that specific image(Which can now be shared). The images are stored in the drawable folder. I want the image I share to be different (smaller - 32px) than the one the user views in its separate activity which is bigger (172px) .

Here is the Activity in which you view the full image in:

public class FullImage extends AppCompatActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.full_image);

        Intent i = getIntent();

        int position = i.getExtras().getInt("id");
        ImageAdapter imageAdapter = new ImageAdapter(this);

        ImageView imageView = (ImageView) findViewById(R.id.full_image_view);
        imageView.setImageResource(imageAdapter.mThumbIds[position]);

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle item selection
        OutputStream output;

        ImageView image = (ImageView) findViewById(R.id.full_image_view);
        Bitmap bitmap = ((BitmapDrawable) image.getDrawable()).getBitmap();

        File dir = new File(Environment.getExternalStorageDirectory() + "/images");

        dir.mkdirs();

        File file = new File(dir, "images.png");

        try {
            verifyStoragePermissions(this);
            output = new FileOutputStream(file);

            bitmap.compress(Bitmap.CompressFormat.PNG, 100, output);
            output.flush();
            output.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        switch (item.getItemId()) {
            case R.id.action_share:
                Uri uri = Uri.fromFile(file);
                Intent shareIntent = new Intent();
                shareIntent.setAction(Intent.ACTION_SEND);
                shareIntent.putExtra(Intent.EXTRA_STREAM, uri);
                shareIntent.setType("image/png");
                startActivity(Intent.createChooser(shareIntent, getResources().getText(R.string.action_share)));

            case android.R.id.home:
                onBackPressed();
                return true;
        }
        return true;

    }

    // Storage Permissions
    private static final int REQUEST_EXTERNAL_STORAGE = 1;
    private static String[] PERMISSIONS_STORAGE = {
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };

    public static void verifyStoragePermissions(Activity activity) {
        // Check if we have write permission
        int permission = ActivityCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);

        if (permission != PackageManager.PERMISSION_GRANTED) {
            // We don't have permission so prompt the user
            ActivityCompat.requestPermissions(
                    activity,
                    PERMISSIONS_STORAGE,
                    REQUEST_EXTERNAL_STORAGE
            );
        }
    }
}

Answer 1

You can scale the bitmap before store it, or store a second reduced image.

int PIXELS = 32;
...
bitmap = bitmap.createScaledBitmap(bitmap, PIXELS , PIXELS , true));
bitmap.compress(Bitmap.CompressFormat.PNG, 100, output);