Android - Set The Source Of An Imageview Inside A Custom Listview Adapter From The Getview Function Does Not Work Properly

Apologies for the long title. I am building an Android application where an activity contains a custom listView. In the layout of my custom listView, I have an image view and thre

Solution 1:

the reason it's not working it's because dealing with image download, cache and view recycling is way way more complex than what your code is handling.

I can point it out a few things I can see it's wrong from your code, but for sure there's more:

• there's no RAM cache, that means the moment the user scrolls a view out if view and then back into view, the image will be downloaded again from the server.
• there's no disk cache, that means that if the user scrolls too far in a list, or if he/she leaves the app for a few minutes to later come back, the image will be downloaded again from the server
• on this line holder.photo.setImageBitmap you're trying to change a View in a background thread.
• AsyncTask (starting on some API) is a mono-thread class, meaning all your downloads will be queue in happen one after the other, so probably the user will be staring at a blank screen for a while before seeing anything.
• you're not canceling the task, so during recycling, the call setImageBitmap might be happening on the wrong item.

replace the line:

new setDisplayPhoto().execute(listData.get(position).getPicture_path());

with:

Picasso.with(convertView.getContext())
    .load("http://192.168.0.10:8888/server/path/here/" +
                       listData.get(position).getPicture_path())
    .into(holder.photo);

for that to work you'll need one extra libary that you can add by adding the following line on your manifest:

compile'com.squareup.picasso:picasso:2.5.2'

for more info on the library check this: http://square.github.io/picasso/

Solution 2:

package com.example.jojo.gridview;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;

publicclassGirdViewAdapterextendsBaseAdapter {
    private Activity activity;
    private ArrayList<String> ar;
    private LayoutInflater inflater;

    publicGirdViewAdapter(ArrayList<String> ar, Activity con)
    {
        activity = con;
        this.ar=ar;
        inflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    privateclassViewHolder {
        public TextView textView;
        public ImageView imageView;
    }

    @OverridepublicintgetCount() {
        // TODO Auto-generated method stubreturn ar.size();
    }

    @Overridepublic Object getItem(int arg0) {
        // TODO Auto-generated method stubreturnnull;
    }

    @OverridepubliclonggetItemId(int arg0) {
        // TODO Auto-generated method stubreturn0;
    }

    @Overridepublic View getView(int position, View arg1, ViewGroup arg2) {
        // TODO Auto-generated method stubViewrowView= arg1;
        ViewHolder viewHolder;
        if (arg1 == null) {
            rowView = inflater.inflate(R.layout.style_view, null);
            viewHolder = newViewHolder();
            viewHolder.textView = (TextView) rowView.findViewById(R.id.textView);
            viewHolder.imageView = (ImageView) rowView.findViewById(R.id.imageView);
            rowView.setTag(viewHolder);
        } elseviewHolder= (ViewHolder) rowView.getTag();
        String rowData[] = this.ar.get(position).split("\\|");
        viewHolder.textView.setText(rowData[0] );
        setImageView(viewHolder.imageView, rowData[1] );
        return rowView;
    }

    privatevoidsetImageView(ImageView imageView, String url) {
        classImageDownloadHelperextendsAsyncTask<String, String, Bitmap> {
            @Overrideprotected Bitmap doInBackground(String... params) {
                // TODO Auto-generated method stub
                URL url;
                String_url= params[0];
                Log.e("url",_url );

                BufferedOutputStream out;
                InputStream in;
                BufferedInputStream buf;

                try {
                    url = newURL(_url);
                    in = url.openStream();
                    buf = newBufferedInputStream(in);

                    BitmapbMap= BitmapFactory.decodeStream(buf);
                    if (in != null) {
                        in.close();
                    }
                    if (buf != null) {
                        buf.close();
                    }
                    return bMap;
                } catch (Exception e) {
                    Log.e("Error reading file", e.toString());
                }
                returnnull;
            }
        }

        ImageDownloadHelperdownloadHelper=newImageDownloadHelper();
        downloadHelper.execute(url);
        try {
            imageView.setImageBitmap(downloadHelper.get());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}