网络图片设置为控件背景图

public static void backgroundNetwork(final View v, String url) {    if (v == null || TextUtils.isEmpty(url)) {        return;    }    new DownloadImageTask() {        @Override        protected void onPostExecute(Drawable result) {            super.onPostExecute(result);            int pTop = v.getPaddingTop();            int pBottom = v.getPaddingBottom();            int pLeft = v.getPaddingLeft();            int pRight = v.getPaddingRight();            v.setPadding(pLeft, pTop, pRight, pBottom);            v.setBackgroundDrawable(result);        }    }.execute(url);}private static Drawable loadImageFromNetwork(String imageUrl) {    Drawable drawable = null;    try {        // 可以在这里通过第二个参数(文件名)来判断，是否本地有此图片        drawable = Drawable.createFromStream(new URL(imageUrl).openStream(), null);    } catch (IOException e) {        Log.d("skythinking", e.getMessage());    }    if (drawable == null) {        Log.d("skythinking", "null drawable");    } else {        Log.d("skythinking", "not null drawable");    }    return drawable;}private static class DownloadImageTask extends AsyncTask<String, Void, Drawable> {    protected Drawable doInBackground(String... urls) {        return loadImageFromNetwork(urls[0]);    }    protected void onPostExecute(Drawable result) {    }}