Question

After i click “more” button, it suppose will extend the listview from 10 to 20.

However after clicked, the list view did not extend and remain original size.

It only can keep the position of scroll bar. This is half of what i need.

newsid = new int[webservice.news.size()];
        title = new String[webservice.news.size()];
        date = new String[webservice.news.size()];
        imagepath = new String[webservice.news.size()];
        for (int i = 0; i < webservice.news.size(); i++) {
            newsid[i] = webservice.news.get(i).getID();
            title[i] = webservice.news.get(i).getNtitle();
            date[i] = webservice.news.get(i).getNArticalD();
            imagepath[i] = webservice.news.get(i).getImagePath();
        }
        adapter = new CustomAdapter_ParticularCategoryAllNews(this, title,
                date, imagepath);
        lv.addFooterView(footermore);
        if (constant.isOnline()) {
            lv.addFooterView(constant.AdMob());
        }
        TextView titletext = (TextView) findViewById(R.id.text_pagetitle);
        titletext.setText(pagetitletext.toString());
        lv.setAdapter(adapter);

This is call when launch activity.

btnmore.setOnClickListener(new OnClickListener() {
    public void onClick(View arg0) {
for (int i = 0; i < webservice.news.size(); i++) {                                                                           
newsid[i] = webservice.news.get(i).getID();
title[i] = webservice.news.get(i).getNtitle();
date[i] = webservice.news.get(i).getNArticalD();
imagepath[i] = webservice.news.get(i).getImagePath();
}       
adapter.setTitle(title);
adapter.setDate(date);
adapter.setImagepath(imagepath);
position = lv.getFirstVisiblePosition();
lv.smoothScrollToPosition(position);
adapter.notifyDataSetChanged();

This is what i call after i click “more button”. However the list did not extend from 10 to 20 items.

public class CustomAdapter_ParticularCategoryAllNews extends BaseAdapter {

private Activity activity;
private String[] title, date, imagepath;
private static LayoutInflater inflater = null;
private ImageLoader_Loader imageLoader;
private WindowManager wm = null;
private Display display;
private Config_ConstantVariable constant;

public CustomAdapter_ParticularCategoryAllNews(Activity a, String[] title,
        String[] date, String[] imagepath) {
    activity = a;
    this.title = title;
    this.date = date;
    this.imagepath = imagepath;
    inflater = (LayoutInflater) activity
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    wm = (WindowManager) activity.getSystemService(Context.WINDOW_SERVICE);
    imageLoader = new ImageLoader_Loader(activity.getApplicationContext());
    constant = new Config_ConstantVariable(activity);
}

public int getCount() {
    return title.length;
}

public Object getItem(int position) {
    return position;
}

public long getItemId(int position) {
    return position;
}

public void setTitle(String[] title) {
    this.title = title;
}

public void setDate(String[] date) {
    this.date = date;
}

public void setImagepath(String[] imagepath) {
    this.imagepath = imagepath;
}

public View getView(int position, View convertView, ViewGroup parent) {
    View vi = convertView;
    if (convertView == null)
        vi = inflater.inflate(R.layout.main_particularcategoryallnewslist,
                parent, false);

    LinearLayout linear = (LinearLayout) vi.findViewById(R.id.layout_image);

    ImageView imageview = (ImageView) vi
            .findViewById(R.id.image_categoryallnewstitle);

    TextView titletext = (TextView) vi
            .findViewById(R.id.text_categoryallnewstitle);

    TextView datetext = (TextView) vi.findViewById(R.id.text_newsdate);

    if (!imagepath[position].toString().equals("no picture")) {
        imageview.setVisibility(View.VISIBLE);
        linear.setVisibility(View.VISIBLE);
        imageLoader.DisplayImage(imagepath[position], imageview);
    } else {
        imageview.setVisibility(View.GONE);
        imageview.setImageDrawable(null);
        linear.setVisibility(View.GONE);
        display = wm.getDefaultDisplay();
        int screenWidth = display.getWidth();
        titletext.setWidth(screenWidth);
    }
    if (constant.getscreenresolution() >= 800 && constant.ScreenOrientation() == 1) {
        titletext.setTextSize(TypedValue.COMPLEX_UNIT_PX, 30);
        datetext.setTextSize(TypedValue.COMPLEX_UNIT_PX, 20);
    }
    titletext.setText(title[position].toString());
    datetext.setText(date[position].toString());
    return vi;
}

}

This is the CustomAdapter class.

Answer 1

In your adapter add:

public void setTitle(String[] title) {
    this.title = title;
}

public void setDate(String[] date) {
    this.date = date;
}

public void setImagepath(String[] imagepath) {
    this.imagepath = imagepath;
}

When the more button is pressed call the three methods above with arrays containing 20 objects. Then call notifyDataSetChanged on your adapter.

Update:

This is working for me:
Activity:

public class HelpProjectActivity extends Activity {

    private ArrayList<Item> items;
    private boolean extend = false;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        createArray();

        ListView lv = (ListView)findViewById(R.id.list);
        lv.setAdapter(new HelpListAdapter());
    }

    private void createArray() {
        items = new ArrayList<Item>();
        for(int i = 0; i < 20; i++) {
            Item item = new Item();
            item.title = "Title " + i;
            item.subtitle = "Subtitle " + i;
            item.image = "default";
            items.add(item);
        }
    }

    public void morePressed(View v) {
        extend = !extend;
        Button b = (Button) findViewById(R.id.button);
        b.setText(extend ? R.string.less_button : R.string.more_button);
        ListView lv = (ListView)findViewById(R.id.list);
        ((BaseAdapter)lv.getAdapter()).notifyDataSetChanged();
    }

    private class HelpListAdapter extends BaseAdapter {

        @Override
        public int getCount() {
            if (extend) {
                return items.size();
            } 
            return items.size()/2;
        }

        @Override
        public Object getItem(int pos) {
            return items.get(pos);
        }

        @Override
        public long getItemId(int pos) {
            return pos;
        }

        @Override
        public View getView(int pos, View convertView, ViewGroup parent) {
            View v = convertView;
            if (v == null) {
                v = View.inflate(getApplicationContext(), R.layout.litst_item, null);
            }
            Item item = items.get(pos);
            TextView titleText = (TextView) v.findViewById(R.id.list_item_title);
            titleText.setText(item.title);
            TextView subtitleText = (TextView) v.findViewById(R.id.list_item_subtitle);
            subtitleText.setText(item.subtitle);
            ImageView image = (ImageView) v.findViewById(R.id.list_image);
            if (item.image.equalsIgnoreCase("default")) {
                image.setImageResource(R.drawable.default_list_image);
            } else {
                // what ever
            }
            return v;
        }

    }
}

main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_margin="10dp"
        android:onClick="morePressed"
        android:text="@string/more_button" />

    <ListView
        android:id="@+id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

list_item.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >

    <ImageView
        android:id="@+id/list_image"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:layout_margin="5dp"
        android:layout_gravity="center_vertical"
        android:contentDescription="@string/list_image" />

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/list_item_title"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/list_item_subtitle"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textStyle="italic" />
    </LinearLayout>

</LinearLayout>

Item.java:

public class Item {
    String image;
    String title;
    String subtitle;
}