将listview项目背景图像设置为从Web下载的可绘制对象

Question

I'm downloading an image from the web and trying to set it as the background to the inflated list element in my ListView adapter. This is my method (from the class extending BaseAdapter :

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
    //working with an object called "hl"
    if (view == null){
        view = myInflater.inflate(R.layout.list_element, null);
    }

    Bitmap background = hl.getBgImage();
    Drawable dr = new BitmapDrawable(background);
    RelativeLayout rl = (RelativeLayout) view.findViewById(R.layout.headline_list);
    rl.setBackgroundDrawable(dr);
    return view;
}

However, I am getting a NullPointerException on the rl.setBackgroundDrawable(dr); line. Is there a problem with the way I'm adding the image? My method to get the bitmap is as follows, the stack trace is never called so I assume that it is downloading properly?

private static Bitmap getBitmapFromURL(String imageUrl) {
    try {
        URL url = new URL(imageUrl);
        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;
    }
}

Thanks for any advice.

Edit: I am calling getBitmapFromUrl(String imageURL) with:

    String image = "http://www.google.com/trends/resources/2327917647-google-icon.png";
    Bitmap bg = getBitmapFromURL(image);
    Object hl = new Object(title, bg);
    objectList.add(hl);

Answer 1

Found the issue. Should have ignored the relativelayout completely.

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
    //working with an object called "hl"
    if (view == null){
        view = myInflater.inflate(R.layout.headline_list, null);
    }

    Bitmap background = hl.getBgImage();
    Drawable dr = new BitmapDrawable(background);
    view.setBackgroundDrawable(dr);
    return view;
}

Answer 2

As I know, the code line "rl.setBackgroundDrawable(dr);" will never throw NullPointerException unless rl is null, even if dr is null. So Please update your xml file R.layout.list_element and let's find the problem together. Good Luck!