使用 ImageGetter 从 HTML 中抓取图像的内存不足错误

Question

我正在编写一个应用程序来显示来自网站的帖子并使用Html.fromHtml 来执行此操作。但是，如果我打开一篇文章，它会立即使用大约 25MB 的内存来加载图像。即使图像存储在设备上，这也是可以接受的，只有重新加载同一篇文章会导致另一个 25MB 的跳转。我环顾四周并尝试了大量建议的解决方案。我觉得我需要回收位图，只是我不确定在哪里执行此操作。代码如下：

public class ImageGetter implements Html.ImageGetter {
private Context c;
private TextView container;
private ImageLoader imageLoader;
private DisplayImageOptions options;
private UrlImageDownloader urlDrawable;

public ImageGetter(View t, Context c) {
    this.c = c;
    this.container = (TextView)t;

    imageLoader = ImageLoader.getInstance();
    options = new DisplayImageOptions.Builder().cacheOnDisk(true).cacheInMemory(false).imageScaleType(ImageScaleType.EXACTLY)
            .showImageOnLoading(R.color.darkcolorPrimary).bitmapConfig(Bitmap.Config.RGB_565).resetViewBeforeLoading(true).build();
}

@Override
public Drawable getDrawable(String source) {
    urlDrawable = new UrlImageDownloader(c.getResources(), source);
    imageLoader.loadImage(source, options, new SimpleListener(urlDrawable));
    return urlDrawable;
}

private class SimpleListener extends SimpleImageLoadingListener
{
    UrlImageDownloader urlImageDownloader;

    public SimpleListener(UrlImageDownloader downloader) {
        super();
        urlImageDownloader = downloader;
    }

    @Override
    public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
        int width = loadedImage.getWidth();
        int height = loadedImage.getHeight();

        int newWidth = width;
        int newHeight = height;

        if( width > container.getWidth() ) {
            newWidth = container.getWidth();
            newHeight = (newWidth * height) / width;
        }

        Drawable result = new BitmapDrawable(c.getResources(), loadedImage);
        result.setBounds(0, 0, newWidth, newHeight);

        urlImageDownloader.setBounds(0, 0, newWidth, newHeight);
        urlImageDownloader.drawable = result;

        container.setText(container.getText());
    }
}

public class UrlImageDownloader extends BitmapDrawable
{
    public Drawable drawable;

    /**
     * Create a drawable by decoding a bitmap from the given input stream.
     *
     * @param res
     * @param is
     */
    public UrlImageDownloader(Resources res, InputStream is) {
        super(res, is);
    }

    /**
     * Create a drawable by opening a given file path and decoding the bitmap.
     *
     * @param res
     * @param filepath
     */
    public UrlImageDownloader(Resources res, String filepath) {
        super(res, filepath);
        drawable = new BitmapDrawable(res, filepath);
    }

    /**
     * Create drawable from a bitmap, setting initial target density based on
     * the display metrics of the resources.
     *
     * @param res
     * @param bitmap
     */
    public UrlImageDownloader(Resources res, Bitmap bitmap) {
        super(res, bitmap);
    }

    @Override
    public void draw(Canvas canvas) {
        // override the draw to facilitate refresh function later
        if(drawable != null) {
            drawable.draw(canvas);
        }
    }
}

}

Answer 1

解决了。存在涉及存储图像的TextView 的内存泄漏。如果您遇到此类问题，我建议您使用 Eclipse MAT 来识别内存泄漏。

Answer 2

您可以通过调用recycle 方法删除位图。 但这本身不会有太大的作用，你应该通过调用System.gc()来调用垃圾收集器，他会将其从内存中清除。