How resize image from gallery?

问题

The first file allow the user to pick a photo from the gallery and sends it to an activity which will process it. The problem is that the image is too large for the phone's screen, so you only see the top corner of the image(as if it has been magnified).

Button useGallery = (Button)findViewById(R.id.loadfromgallery);
        useGallery.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {

                Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
                photoPickerIntent.setType("image/*");
                startActivityForResult(photoPickerIntent, SELECT_PHOTO); 
            }}) ;

 @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) { 
        super.onActivityResult(requestCode, resultCode, imageReturnedIntent); 

        switch(requestCode) { 
        case SELECT_PHOTO:
            if(resultCode == RESULT_OK){  
                Uri selectedImage = imageReturnedIntent.getData();
                InputStream imageStream = null;
                try {
                    imageStream = getContentResolver().openInputStream(selectedImage);
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                Bitmap yourSelectedImage = BitmapFactory.decodeStream(imageStream);
                Intent intent = new Intent(mContext, DisplayUndistortedBitmapFromGalleryActivity.class);
                intent.setData(selectedImage);
                startActivity(intent);

                if(yourSelectedImage != null){
                Log.e(TAG,"pic ok");
                }else{
                     Log.e(TAG,"pic not ok");
                }
            }
        }

. The 2nd file is the activity that recieves the image data from the intent and places it in a URI that a bitmap is the derived from.

public class DisplayUndistortedBitmapFromGalleryActivity extends Activity {

    private static final String TAG = "*********DUBFGActivity";
    private Context mContext = this;
    Uri uri;
    private Bitmap mbitmap = null;

    @Override 
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);


         uri = getIntent().getData();
        if(uri != null){
            Log.e(TAG, "uri ok");
        }else {
            Log.e(TAG, "uri not ok");
        }


        try {
              mbitmap = Media.getBitmap(getContentResolver(), uri);
             //setMbitmap(bitmap);
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

.

I have a 3rd file which is the customview for the activity. The line below retrieves the bitmap from it's activity and displays it. Is there a way of downsizing the bitmap so it fits on the screen? thanks.

Bitmap bm = ((DisplayUndistortedBitmapFromGalleryActivity)getContext()).getMbitmap();

回答1:

Here is how i usually resize a bitmap and is the easiest way.

public class bitmaptest extends Activity {
@Override
public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    LinearLayout linLayout = new LinearLayout(this);

    // load the origial BitMap (500 x 500 px)
    Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
           R.drawable.android);

    int width = bitmapOrg.width();
    int height = bitmapOrg.height();
    int newWidth = 200;
    int newHeight = 200;

    // calculate the scale - in this case = 0.4f
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;

    // createa matrix for the manipulation
    Matrix matrix = new Matrix();
    // resize the bit map
    matrix.postScale(scaleWidth, scaleHeight);
    // rotate the Bitmap


    // recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
                      width, height, matrix, true);

    // make a Drawable from Bitmap to allow to set the BitMap
    // to the ImageView, ImageButton or what ever
    BitmapDrawable bmd = new BitmapDrawable

EDIT:

Here is another option.

  int targetWidth  = bitmapOrg.getWidth() - 15; //change this to control the size
  int targetHeight = bitmapOrg.getHeight() - 15 ;
  Matrix matrix = new Matrix();
  matrix.postScale(1f, 1f);
  Bitmap resizedBitmap = Bitmap.createBitmap(bmp, 0, 0, targetWidth, targetHeight, matrix, true);

来源：https://stackoverflow.com/questions/8523545/how-resize-image-from-gallery