Is it possible to insert a column in a listview at runtime?

Question

I want the listview to look like a datagrid control in android. All columns are generated using code-behand, which is dynamic. My code snippets can be successfully created, but the list is not displayed as I expected. What is wrong with him?

@Override public View getView(int position, View convertView, ViewGroup parentView) { ViewHolder holder = null; if (convertView == null) { synchronized (MainActivity.this) { convertView = mInflater.inflate(id_row_layout, null); holder = new ViewHolder(); //I had add an textView to the convertView,but it not show LinearLayout layout = (LinearLayout) convertView.findViewById(R.id.rLayout); TextView tx = new TextView(context); tx.setText("ads"); layout.addView(tx); MyHScrollView scrollView1 = (MyHScrollView) convertView .findViewById(R.id.horizontalScrollView1); holder.scrollView = scrollView1; holder.txt1 = (TextView) convertView .findViewById(R.id.textView1); holder.txt2 = (TextView) convertView .findViewById(R.id.textView2); holder.txt3 = (TextView) convertView .findViewById(R.id.textView3); holder.txt4 = (TextView) convertView .findViewById(R.id.textView4); holder.txt5 = (TextView) convertView .findViewById(R.id.textView5); MyHScrollView headSrcrollView = (MyHScrollView) mHead .findViewById(R.id.horizontalScrollView1); headSrcrollView .AddOnScrollChangedListener(new OnScrollChangedListenerImp( scrollView1)); convertView.setTag(holder); mHolderList.add(holder); } } else { holder = (ViewHolder) convertView.getTag(); } holder.txt1.setText(position + "" + 1); holder.txt2.setText(position + "" + 2); holder.txt3.setText(position + "" + 3); holder.txt4.setText(position + "" + 4); holder.txt5.setText(position + "" + 5); return convertView; } 

Answer 1

 1) In your adapter with Arraylist override the appropriate constructor 2) In your activity, make your variable data a field (type ArrayList 3) When you add a location you can use data.add(location) 4) Then you can call notifyDatasetChanged() on your adapter 

Code example: http://androidadapternotifiydatasetchanged.blogspot.in/

Answer 2

Works for me in ApiDemos with an extra textView;

 public class List14 extends ListActivity { private static class EfficientAdapter extends BaseAdapter { private LayoutInflater mInflater; private Bitmap mIcon1; private Bitmap mIcon2; private Context context; public EfficientAdapter(Context context) { // Cache the LayoutInflate to avoid asking for a new one each time. mInflater = LayoutInflater.from(context); this.context = context; // Icons bound to the rows. mIcon1 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_1); mIcon2 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_2); } /** * The number of items in the list is determined by the number of speeches * in our array. * * @see android.widget.ListAdapter#getCount() */ public int getCount() { return DATA.length; } /** * Since the data comes from an array, just returning the index is * sufficent to get at the data. If we were using a more complex data * structure, we would return whatever object represents one row in the * list. * * @see android.widget.ListAdapter#getItem(int) */ public Object getItem(int position) { return position; } /** * Use the array index as a unique id. * * @see android.widget.ListAdapter#getItemId(int) */ public long getItemId(int position) { return position; } /** * Make a view to hold each row. * * @see android.widget.ListAdapter#getView(int, android.view.View, * android.view.ViewGroup) */ public View getView(int position, View convertView, ViewGroup parent) { // A ViewHolder keeps references to children views to avoid unneccessary calls // to findViewById() on each row. ViewHolder holder; // When convertView is not null, we can reuse it directly, there is no need // to reinflate it. We only inflate a new View when the convertView supplied // by ListView is null. if (convertView == null) { convertView = mInflater.inflate(R.layout.list_item_icon_text, null); // Creates a ViewHolder and store references to the two children views // we want to bind data to. holder = new ViewHolder(); holder.text = (TextView) convertView.findViewById(R.id.text); holder.icon = (ImageView) convertView.findViewById(R.id.icon); LinearLayout layout = (LinearLayout) convertView.findViewById(R.id.layout); TextView child = new TextView(context); child.setText("CHILD"); layout.addView(child); convertView.setTag(holder); } else { // Get the ViewHolder back to get fast access to the TextView // and the ImageView. holder = (ViewHolder) convertView.getTag(); } // Bind the data efficiently with the holder. holder.text.setText(DATA[position]); holder.icon.setImageBitmap((position & 1) == 1 ? mIcon1 : mIcon2); return convertView; } static class ViewHolder { TextView text; ImageView icon; } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setListAdapter(new EfficientAdapter(this)); } private static final String[] DATA = { "Abbaye de Belloc", "Abbaye du Mont des Cats", "Abertam", }; } 

Check out your static holder and layouts .

Answer 3

It’s easy to have an extra column, just show and hide the item for the selected position. You must hide them as soon as the item is not shown.

In fact, you can also inflate a RelativeLayout from your adapter, but this may be harder to achieve.

Hope that helps

Answer 4

If your Row file layout is the same for each line, then

you can just add the number of elements (in other words, your column)

to your ArrayList (which is responsible for populating the listview adapter ) and just call notifydatasetchanged(true) or adapter.notifyDataSetChanged()