在listview中按位置

Question

我正在尝试使用LruCache进行延迟加载，如下所示：Example using Androids lrucache。

public class TCImageLoader implements ComponentCallbacks2 {
    private TCLruCache cache;
    Context cv;
    public TCImageLoader(Context context) {
        ActivityManager am = (ActivityManager) context.getSystemService(
            Context.ACTIVITY_SERVICE);
        int maxKb = am.getMemoryClass() * 1024;
        int limitKb = maxKb / 8; // 1/8th of total ram
        cache = new TCLruCache(limitKb);
        cv = context;
    }

    public void display(String url, ImageView imageview, int defaultresource) {
        imageview.setImageResource(defaultresource);
        Bitmap image = cache.get(url);
        if (image != null) {
            imageview.setImageBitmap(image);
        }
        else {
            new SetImageTask(imageview).execute(url);
        }
    }

    private class TCLruCache extends LruCache<String, Bitmap> {

        public TCLruCache(int maxSize) {
            super(maxSize);
        }

        @Override
        protected int sizeOf(String key, Bitmap value) {
            int kbOfBitmap = value.getByteCount() / 1024;
            return kbOfBitmap;
        }
    }

    private class SetImageTask extends AsyncTask<String, Void, Integer> {
        private ImageView imageview;
        private Bitmap bmp;
        public SetImageTask(ImageView imageview) {
            this.imageview = imageview;
        }

        @Override
        protected Integer doInBackground(String... params) {
            String url = params[0];
            try {
                //bmp = BitmapFactory.decodeResource(cv.getResources(), url);
                bmp = getBitmapFromURL(url);
                if (bmp != null) {
                    cache.put(url, bmp);
                }
                else {
                    return 0;
                }
            } catch (Exception e) {
                e.printStackTrace();
                return 0;
            }
            return 1;
        }

        @Override
        protected void onPostExecute(Integer result) {
            if (result == 1) {
                imageview.setImageBitmap(bmp);
            }
            //super.onPostExecute(result);
        }

        private Bitmap getBitmapFromURL(String src) {
            try {
                URL url = new URL(src);
                HttpURLConnection connection
                    = (HttpURLConnection) url.openConnection();
                connection.setDoInput(true);
                connection.connect();
                InputStream input = connection.getInputStream();
                Bitmap myBitmap = BitmapFactory.decodeStream(input);
                return myBitmap;
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
        }

    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
    }

    @Override
    public void onLowMemory() {
    }

    @Override
    public void onTrimMemory(int level) {
    /*    if (level >= TRIM_MEMORY_MODERATE) {
            cache.evictAll();
        }
        else if (level >= TRIM_MEMORY_BACKGROUND) {
            cache.trimToSize(cache.size() / 2);
        }*/
    }
}

TCimageloader如上面的代码所示。我的getview如下所示：

public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {
            // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(200, 200));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
//            imageView.setPadding(10,10,10,10);
        } else {
            imageView = (ImageView) convertView;
        }
       imagloader = new TCImageLoader(mContext);
        imagloader.display(mThumbIds[position], imageView, R.drawable.ic_launcher);
        //Picasso.with(mContext).load(mThumbIds[position]).placeholder(R.drawable.ic_launcher).into(imageView);
        imageView.setImageResource(R.drawable.ic_launcher);
        return imageView;
    }

但我面临的问题是，当我快速滚动时，getView已经被调用并且已经调用了显示方法。所以图像视图会一直在变化，直到实现最后一次调用。

我正在尝试制作自定义图库，这也有助于我从网址下载图片。我将不得不使用相同的方法。只需要将文件地址更改为URL地址