Question

I am tring to get the image width and height in android and load accordingly buy my below code is working fine in 2.3.3 but when i test in higher version(4.0) its height and width are giving null pointer exception…Below is my code…

           Drawable drawable = null; 
           drawable = LoadImageFromWebOperations(logo_url.replace(" ", "%20"));
           System.out.println("Width" + drawable.getMinimumWidth());
           System.out.println("Height" + drawable.getMinimumHeight()); 
           int width = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, drawable.getMinimumWidth(), mCtx.getResources().getDisplayMetrics());
           int height = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, drawable.getMinimumHeight(), mCtx.getResources().getDisplayMetrics());
           client_logo.setMinimumHeight(height);
           client_logo.setMinimumWidth(width);
           client_logo.setImageDrawable(drawable); 


            public Drawable LoadImageFromWebOperations(String url){
System.out.println(url);

    try{
        InputStream is = (InputStream) new URL(url).getContent();
        Drawable d = Drawable.createFromStream(is, "src name");
        return (d);
    }catch (Exception e) {
        //System.out.println("Exc="+e);
        return null;
    }
}

Answer 1

As of API 11, if you are executing this code on the UI thread, the network access will throw a NetworkOnMainThreadException. You don’t post your logcat output (which would be very helpful), but I suspect this is what’s happening. As a result, LoadImageFromWebOperations will return null and you will get a NPE when you try to access the drawable properties.

You need to run this code in a worker thread. See the article Keeping Your App Responsive.