Slideshow with images from Urls

Question

I was developing a slideshow loading images from Urls I found a library developed by a Russian, the Universal Image Loader, however this slideshow will be used in the application in the version of tablet. In the mobile version I use a listview.

The only problem is that the slideshow was giving error in version 3.0 which is precisely the minimum version for tablet.

I make the connection with the webservice and bring from the database the Urls that change constantly, then I use the pager and the library classes.

    String[] imageUrls = new String[logos.size()];//logos é um List<String> que contem as urls
    imageUrls = (String[]) logos.toArray(imageUrls);
    //String[] imageUrls = bundle.getStringArray(Extra.IMAGES);
    int pagerPosition = bundle.getInt(Extra.IMAGE_POSITION, 0);

    if (savedInstanceState != null) {
        pagerPosition = savedInstanceState.getInt(STATE_POSITION);
    }

    options = new DisplayImageOptions.Builder()
        .showImageForEmptyUri(R.drawable.stub)
        .showImageOnFail(R.drawable.stub)
        .resetViewBeforeLoading(true)
        .cacheOnDisc(true)
        .imageScaleType(ImageScaleType.EXACTLY)
        .bitmapConfig(Bitmap.Config.RGB_565)
        .considerExifParams(true)
        .displayer(new FadeInBitmapDisplayer(300))
        .build();

    pager = (ViewPager) findViewById(R.id.pager);
    pager.setAdapter(new ImagePagerAdapter(imageUrls));
    pager.setCurrentItem(pagerPosition);

Is there any other way to make a slideshow or some alternative, for example a grid well structured uploading images from Urls?

Picture of the error that is giving

Answer 1

NetworkOnMainThreadException occurs when the app tries to do some network operation on the main thread (the one that runs the interface).

This Exception was introduced into Honeycomb to prevent time-consuming operations from occurring on the main thread which would consequently crash the interface.

A quick solution is to disable Strictmode (which generates Exception):

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy)

But I don’t recommend this type of approach because it would hurt the user experience and could even cause an ANR.

One best solution would look for where it is performing the network operation and place this piece of code within a AsyncTask. I would guess that the stretch you take the information from the webservice would cause the problem. A second kick would be within the Adapter in the section where you upload the image, but I believe that Universalimageloader already does network operations in a separate Thread.

Answer 2

In the Twitter Bootstrap has exactly what you need. Take a look there. It’s self-explanatory.