android 加载超大图片内存溢出问题

1.先把图片资源转换成输入流

LargeImageView largeImageView = (LargeImageView) findViewById(R.id.liv);
InputStream inputStream = getResources().openRawResource(R.raw.register_background);
largeImageView.setInputStream(inputStream);

2.使用

private static final BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.RGB_565;
/**
 * 绘制的区域
 */
private volatile Rect mRect = new Rect();

//默认直接显示图片的中心区域，可以自己去调节
mRect.left = 0;
mRect.top = imageHeight / 2 - height / 2;
mRect.right = width;
mRect.bottom = mRect.top + height;

public void setInputStream(InputStream is) {
    try {
        
	BitmapRegionDecoder mDecoder = BitmapRegionDecoder.newInstance(is, false); 
        BitmapFactory.Options tmpOptions = new BitmapFactory.Options();
        // Grab the bounds for the scene dimensions
        tmpOptions.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(is, null, tmpOptions);
        mImageWidth = tmpOptions.outWidth;
        mImageHeight = tmpOptions.outHeight;

   
	Bitmap bm = mDecoder.decodeRegion(mRect, options);//修改mRect的边界值即可动态的展示图片区域
    } catch (IOException e) {
        e.printStackTrace();
    } finally {

        try {
            if (is != null) is.close();
        } catch (Exception e) {
        }
    }
}