Android 2.2 SDK - 位图图像调整大小 nullPointerException

Question

我正在从不同大小的 URLS 加载图像。似乎较小的出现了，而较大的出现了 nullPointerException(显示在下面的 Log.d 中)。如何调整这些图片的大小？

                BitmapDrawable drawable = null;
                Bitmap bitmap = null;
                try {
                    bitmap = loadBitmapFromWeb(url);
                    System.out.println("url " + url);
                } catch (IOException e) {
                }

                int width = 150;
                int height = 150;
                try {
                    drawable = resizeImage(bitmap, height, width);
                } catch (Exception e) {
                    Log.d("exception image", e.toString());
                    drawable = getDrawableFromResource(R.drawable.default_backup);
                }

这是我用来从 URL 加载的内容:

    public static Bitmap loadBitmapFromWeb(String url) throws IOException {
        InputStream is = (InputStream) new URL(url).getContent();
        Bitmap bitmap = BitmapFactory.decodeStream(is);

        return bitmap;
    }

这是我用来调整大小，出现错误的地方:

    public static BitmapDrawable resizeImage(Bitmap bitmap, int w, int h) {

        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        int newWidth = w;
        int newHeight = h;

        float scaleWidth = ((float) newWidth) / width;
        float scaleHeight = ((float) newHeight) / height;

        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);

        Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height,
                matrix, true);

        return new BitmapDrawable(resizedBitmap);
    }

Answer 1

为什么不使用可用的位图函数来调整大小。假设您下载了正确的图像，您只需执行以下操作:

    Bitmap scaledImage = Bitmap.createScaledBitmap(originalImage, newWidth, newHeight, false);