Listview avec case à cocher en utilisant monodroid?

Question

Je dois implémenter listview avec les cases à cocher. Si je coche 4 cases sur 10, après avoir cliqué sur un bouton, alors quelles que soient les cases à cocher cochées, il faut trouver ces détails de ligne (objet). J'ai beaucoup cherché mais je ne pouvais pas trouver de solution en monodroid. S'il vous plaît aidez-moi.

Answer 1

vous devez utiliser ce type d'adaptateur ETUI ARRIVÉE LISTVIEW: Méthode VOICI getView pour BaseAdapter:

 ViewHolder viewHolder = null; 
    if (convertView == null) { 
     LayoutInflater inflator = context.getLayoutInflater(); 
     convertView = inflator.inflate(R.layout.row, null); 
     viewHolder = new ViewHolder(); 
     viewHolder.text = (TextView) convertView.findViewById(R.id.label); 
     viewHolder.checkbox = (CheckBox) convertView.findViewById(R.id.check); 
     viewHolder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { 

      @Override 
      public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { 
       int getPosition = (Integer) buttonView.getTag(); // Here we get the position that we have set for the checkbox using setTag. 
       list.get(getPosition).setSelected(buttonView.isChecked()); // Set the value of checkbox to maintain its state. 
      } 
     }); 
     convertView.setTag(viewHolder); 
     convertView.setTag(R.id.label, viewHolder.text); 
     convertView.setTag(R.id.check, viewHolder.checkbox); 
     } else { 
     viewHolder = (ViewHolder) convertView.getTag(); 
    } 
    viewHolder.checkbox.setTag(position); // This line is important. 

    viewHolder.text.setText(list.get(position).getName()); 
    viewHolder.checkbox.setChecked(list.get(position).isSelected()); 

Answer 2

Donc résoudre votre problème, malheureusement, implique beaucoup de détails. J'ai lutté avec moi-même. Je n'ai pas de projet d'exemple, mais j'ai essayé de retirer des parties inutiles d'une solution de travail. J'espère que cela aidera au moins la vue d'ensemble de la structure que j'ai créée.

Adaptateur

public class MyItemListAdapter : BaseAdapter 
{ 
    private OrderedDictionary<Guid, ObjectRespresentingSingleRow> _items = new OrderedDictionary<Guid, ObjectRespresentingSingleRow>(); 
    private GuidHashSet _selectedItems = new GuidHashSet(); 

    public ICollection<ObjectRespresentingSingleRow> Items 
    { 
     get { return _itmes.Values; } 
    } 

    public event EventHandler<IntegerEventArgs> SelectedItemsChanged; 
    public event EventHandler<IntegerEventArgs> ItemsNumberChanged; 

    public void Add(ObjectRespresentingSingleRow item) 
    { 
     _items.Add(item.Id, item); 
     // Fire the ItemsNumberChanged event here 
     NotifyDataSetChanged(); 
    } 

    public void SelectAll() 
    { 
     _selectedItems.UnionWith(_items.Keys); 
     // Fire SelectedEventsChanged here 
     NotifyDataSetChanged(); 
    } 

    public void ClearSelected() 
    { 
     _selectedItems.Clear(); 
     // Fire SelectedEventsChanged here 
     NotifyDataSetChanged(); 
    } 

    // Will need to add all the overrides as well as some methods like (RemoveAllSelected(), SelectAt(), Clear(), ... etc) 

    public override View GetView(int position, View convertView, ViewGroup parent) 
    { 
     ItemViewHolder viewHolder; 
     ObjectRespresentingSingleRow listItem = _items[position].Value; 
     if (convertView == null) 
     { 
      viewHolder = new ItemViewHolder(); 
      convertView = _inflater.Inflate(Resource.Layout.LayoutItemListViewRow, null); 

      viewHolder.CheckBox = convertView.FindViewById<CheckBox>(Resource.Id.ItemListViewRowCheckBoxSelected); 
      viewHolder.OtherView = convertView.FindViewById<TextView>(Resource.Id.ItemListViewRowTextViewName); 

      // I also had to use a TouchDelegate on the CheckBox to extend the checkbox touchable area 

      // Save the view holder so that we do not have to find these view again for this particular item 
      convertView.Tag = viewHolder; 
     } 
     else 
     { 
      // Use the previous view holder (performance) 
      viewHolder = (ItemViewHolder)convertView.Tag; 
     } 

     // Since the views are reusable we need to rotate the click handlers for the views 
     viewHolder.CheckBox.Click -= viewHolder.ClickHandler; 
     viewHolder.ClickHandler = (object sender, EventArgs args) => 
     { 
      CheckBox checkBox = (CheckBox)sender; 
      if (checkBox.Checked) 
      { 
       _selectedItems.Add(listItem.Id); 
      } 
      else 
      { 
       _selectedItems.Remove(listItem.Id); 
      } 
      // Fire SelectedItemsChanged event here with the current number of selected items 
     }; 
     viewHolder.CheckBox.Click += viewHolder.ClickHandler; 

     // Popolate the view based on the event data 
     viewHolder.OtherView.Text = listItem.Text; 
     viewHolder.CheckBox.Checked = _selectedItems.Contains(listItem.Id); 
     // Populate the rest of the view ... etc 

     return convertView; 
    } 
} 

Activité/Fragment qui affiche la liste

private MyItemListAdapter _itemListAdapter = null; 
    private ItemListActionCallback _actionCallback = null; 

private void OnCreate() 
{ 
    _itemListAdapter = new MyItemListAdapter(Activity); 
     _itemListAdapter.ItemsNumberChanged += OnItemsNumberChanged; 
     _itemListAdapter.SelectedItemsChanged += OnSelectedItemsChanged; 
     mainListView.ItemClick += OnItemsClicked; // Navigate to the item as well when area away from checkbox is touched 
     mainListView.Adapter = _itemListAdapter; 
} 

private void OnItemsNumberChanged(object sender, IntegerEventArgs args) 
    { 
     // Display empty if args.Value == 0 or something like it 
    } 


private void OnSelectedItemsChanged(object sender, IntegerEventArgs args) 
    { 
     if (args.Value == 0) 
     { 
      if (_actionMode != null) 
      { 
       // The last selected event was unselected, therefore exit action mode 
       _actionMode.Finish(); 
      } 
     } 
     else 
     { 
      if (_actionMode == null) 
      { 
       // At least one event was selected, start action mode 
       _actionMode = Activity.StartActionMode(_actionCallback); 
      } 
      // Update the action bar with the total number of selected events 
      _actionMode.Title = args.Value; // Format this 
     } 
    } 

Si vous voulez faire quelque chose pour les objets sélectionnés via la barre d'action, vous devrez mettre en œuvre ce que bien.

public class ItemListActionCallback : Java.Lang.Object, ActionMode.ICallback 
{ 
    private readonly MyItemListAdapter _adapter = null; 

    public bool OnActionItemClicked(ActionMode mode, IMenuItem item) 
    { 
     switch (item.ItemId) 
     { 
      case Resource.Id.MenuDelete: 
       // Delete from local storage as well as from the adapater 
       _adapter.RemoveSelected(); 
       _adapter.NotifyDataSetChanged(); 
       mode.Finish(); 
       break; 
      case Resource.Id.MenuSelectAll: 
       _adapter.SelectAll(); 
       break; 
      default: 
       mode.Finish(); 
       break; 
     } 
     return true; 
    } 

    // See other examples on how to implement the rest 
} 

Assurez-vous également que votre CheckBox a les éléments suivants:

android:focusable="false" 

Cela imite essentiellement ce que fait Gmail.