如何调整图库的图像大小？

Question

第一个文件允许用户从图库中挑选照片，并将其发送到将对其进行处理的活动。 问题在于该图像对于手机的屏幕而言太大，因此您只能看到该图像的顶角（就好像它已经被放大了一样）。

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");
                }
            }
        }

。 第二个文件是一个活动，它从意图中接收图像数据并将其放置在从中派生位图的URI中。

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();
        }

。

我有第三个文件，它是活动的customview。 下面的行从其活动中检索位图并显示它。 有没有办法缩小位图的大小，使其适合屏幕显示？ 谢谢。

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

Answer 1

这是我通常如何调整位图的大小，这是最简单的方法。

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

编辑：

这是另一种选择。

  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);