List getting slow on scroll while loading images from drawable

Question

I have around 300 images in Drawable and need to show them in a listview, but its getting too slow on scrolling. is there any way to use lazyLoading of offline application.

here's my getView method - if i don't show the image the listview is scrolling fine.

    @Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View vi = convertView;
    ViewHolder holder;

    if(convertView==null){

        /****** Inflate tabitem.xml file for each row ( Defined below ) *******/
        vi = inflater.inflate(R.layout.pos_list_item, null);

        /****** View Holder Object to contain tabitem.xml file elements ******/

        holder = new ViewHolder();
        holder.text = (TextView) vi.findViewById(R.id.textView1);
        holder.text1=(TextView)vi.findViewById(R.id.textView2);
        holder.image=(ImageView)vi.findViewById(R.id.imageView1);


       /************  Set holder with LayoutInflater ************/
        vi.setTag( holder );
    }
    else 
        holder=(ViewHolder)vi.getTag();

    if(data.size()<=0)
    {
        holder.text.setText("No Data");

    }
    else
    {
        /***** Get each Model object from Arraylist ********/
        tempValues=null;
        tempValues = (DataStructureList) data.get( position );

        /************  Set Model values in Holder elements ***********/

         holder.text.setText( tempValues.getPosName());
         holder.text1.setText( tempValues.getCatName());

         int resourceId1 = res.getIdentifier(tempValues.getPosImage()+"1", "drawable",     activity.getPackageName());
         holder.image.setImageResource(resourceId1);

         /******** Set Item Click Listner for LayoutInflater for each row *******/

    }
    return vi;
}'

Hi @PratikBhat I don't need to fetch a URL, I already have all the images in drawable-hdpi folder. but once the complete list is loaded its not smoothly scrolling. — user1878067, Mar 30 '14 at 18:21
My mistake, post some code, have you used recycled views properly? — Pratik Bhat, Mar 30 '14 at 18:25

score 1 · Answer 1 · answered Mar 31 '14 at 06:35

1

 setImageResource (int resId) this runs on UI thread which may slow the UI.

Use

 setImageDrawable(<drawable>);

answered Mar 31 '14 at 06:35

Akhilesh Mani

3,502
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score 0 · Accepted Answer · answered Apr 01 '14 at 05:27

These can be some of the factors for slow scrolling in your code :

setImageResource() does Bitmap reading and decoding on the UI thread, which can cause a latency hiccup. If that's a concern, consider using setImageDrawable(android.graphics.drawable.Drawable) or setImageBitmap(android.graphics.Bitmap) and BitmapFactory instead.
Size and resolution of your images can also be a cause of slow scrolling, try creating thumbnails images of your large images and use.
try to using pagination instead of loading complete data.

List getting slow on scroll while loading images from drawable

2 Answers2