Question

我正在使用LoadImage方法从网址加载图片并将其存储在Bitmap对象中。然后我减小它的大小。获得缩小的图像尺寸后，我将其显示在我的布局的ImageView中。现在我想知道图像尺寸是否减小了。我怎么检查呢？

public class ReduceImageActivity extends Activity {

    String image_URL = "http://pennapps.com/biblioteka/images/C.jpg";

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ImageView bmImage = (ImageView) findViewById(R.id.imageView1);
        BitmapFactory.Options bmOptions;
        bmOptions = new BitmapFactory.Options();
        bmOptions.inSampleSize = 1;
        Bitmap bm = LoadImage(image_URL, bmOptions);
        getResizedBitmap(bm, 200, 200);

        System.out.println("after resizing it"+bm);


        bmImage.setImageBitmap(getResizedBitmap(bm, 200, 200));
    }

    private Bitmap LoadImage(String URL, BitmapFactory.Options options) {
        Bitmap bitmap = null;
        InputStream in = null;
        try {
            in = OpenHttpConnection(URL);
            bitmap = BitmapFactory.decodeStream(in, null, options);
            in.close();
        } catch (IOException e1) {
        }
        return bitmap;
    }

    private InputStream OpenHttpConnection(String strURL) throws IOException {
        InputStream inputStream = null;
        URL url = new URL(strURL);
        URLConnection conn = url.openConnection();

        try {
            HttpURLConnection httpConn = (HttpURLConnection) conn;
            httpConn.setRequestMethod("GET");
            httpConn.connect();

            if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                inputStream = httpConn.getInputStream();
            }
        } catch (Exception ex) {
        }
        return inputStream;
    }

    public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {

        int width = bm.getWidth();

        int height = bm.getHeight();

        float scaleWidth = ((float) newWidth) / width;

        float scaleHeight = ((float) newHeight) / height;

        // create a matrix for the manipulation

        Matrix matrix = new Matrix();

        // resize the bit map

        matrix.postScale(scaleWidth, scaleHeight);

        // recreate the new Bitmap

        Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height,
                matrix, false);

        System.out.println("in getresizebitmap"+resizedBitmap.toString());



        return resizedBitmap;

    }

}

Answer 1

缩小图像尺寸后，可以使用以下方法检查新（缩小）图像的大小; getWidth() getHeight() 使用 - ＆gt; resizedBitmap.getWidth(), resizedBitmap.getHeight()

Answer 2

使用getWidth，getHeight作为@barzos建议。请注意，对getResizedBitmap(bm, 200, 200)的调用不会更改原始bm位图，而是会生成一个新位图，因此请按以下方式使用：

Bitmap bm = LoadImage(image_URL, bmOptions);
Bitmap resized = getResizedBitmap(bm, 200, 200);

System.out.println("after resizing [w: " + resized.getWidth() + ", h: " + resized.getHeight() + "]");

bmImage.setImageBitmap(resized);

这也消除了对getResizedBitmap的一次不必要的调用，从而节省了CPU和内存资源。

如何在Android中减小尺寸后知道位图大小？

2 个答案: