如何获取多个选定的已选中项目（Android）？

Question

I followed this tutorial chapter 14, http://www.vogella.com/tutorials/AndroidListView/article.html#listviewselection but I am trying to figure out how to implement my submit button to grab the checked items...

This was my attempt but apparently the checked items return as false in my submit button, not sure what is going on exactly and looking through google and SO I only found answers to having a regular adapter.

Here is the code:

public class RegisterFollowup extends ListActivity implements OnClickListener {
Button btnCategoriesSubmit;
ListView categoriesList;

//adapter with custom model
ArrayAdapter<MultiSelectItem> adapter;

//list with custom model
List<MultiSelectItem> list;

ArrayList<MultiSelectItem> selected;


public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_followup);

    //setup portrait mode for app
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

    //button categories submit
    btnCategoriesSubmit = (Button) findViewById(R.id.btnCategoriesSubmit);
    btnCategoriesSubmit.setOnClickListener(this);

    //Set adapter for multi-select model and adapter
    adapter = new MultiSelectAdapter(this, getMultiSelectItem());
    setListAdapter(adapter);

    //get the list view and set it in activity to a listview
    //categoriesList = getListView();

    //setChoicemode
    //getListView().setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);

    selected = new ArrayList<MultiSelectItem>();

}

//call to retrieve list
private List<MultiSelectItem> getMultiSelectItem() {
    //initiate new list
    list = new ArrayList<MultiSelectItem>();

    //called to get string array
    Resources res = getResources();
    String[] categories = res.getStringArray(R.array.categories);

    //loop through string array
    for(String category: categories) {
        Log.e("cat", "categ: " + category);
        list.add(get(category));
    }
    return list;
}

//call model to set names and methods for each item
private MultiSelectItem get(String s) {
    return new MultiSelectItem(s);
}

@Override
public void onClick(View view) {
    if(view == btnCategoriesSubmit) {
        Log.e("string results", "string results " + getMultiSelectItem().size());
        for(int i=0;i< getMultiSelectItem().size();i++){
            MultiSelectItem item = getMultiSelectItem().get(i);
            if(item.isSelected()){
                selected.add(item);
            }
        }

        Log.e("string results", "string results selected " + selected.size());
       }
      } 
    }

Here is my code for the adapter:

public class MultiSelectAdapter extends ArrayAdapter<MultiSelectItem> {

private final List<MultiSelectItem> list;
private final Activity context;


public MultiSelectAdapter(Activity context, List<MultiSelectItem> list) {
    super(context, R.layout.multi_select_layout, list);
    this.context = context;
    this.list = list;
}

static class ViewHolder {
    protected TextView text;
    protected CheckBox checkbox;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = null;
    if (convertView == null) {
        LayoutInflater inflater = context.getLayoutInflater();
        view = inflater.inflate(R.layout.multi_select_layout, null);
        final ViewHolder viewHolder = new ViewHolder();
        viewHolder.text = (TextView) view.findViewById(R.id.label);
        viewHolder.checkbox = (CheckBox) view.findViewById(R.id.check);
        viewHolder.checkbox
                .setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

                    @Override
                    public void onCheckedChanged(CompoundButton buttonView,
                                                 boolean isChecked) {
                        MultiSelectItem element = (MultiSelectItem) viewHolder.checkbox
                                .getTag();
                        element.setSelected(buttonView.isChecked());

                    }
                });
        view.setTag(viewHolder);
        viewHolder.checkbox.setTag(list.get(position));
    } else {
        view = convertView;
        ((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));

    }
    ViewHolder holder = (ViewHolder) view.getTag();
    holder.text.setText(list.get(position).getName());
    holder.checkbox.setChecked(list.get(position).isSelected());
    return view;
}
}

Here is the model:

public class MultiSelectItem {
private String name;
private boolean selected;

public MultiSelectItem(String name) {
    this.name = name;
    selected = false;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public boolean isSelected() {
    return selected;
}

public void setSelected(boolean selected) {
    this.selected = selected;
}
}

Answer 1

ArrayList<MultiSelectedItem> selected = new ArrayList<MultiSelectedItem>();


@Override
public void onClick(View view) {
    if(view == btnCategoriesSubmit) {
       for(int i=0;i< getMultiSelectItem().size;i++){
           MultiSelectItem item = getMultiSelectItem().get(i);
           if(item.isSelected()){
               selected.add(item);
           }
       }
    }
}

does that make any sence to you ? :)

EDIT:

@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView == null) {

            LayoutInflater vi = (LayoutInflater) getActivity()
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = vi.inflate(R.layout.multi_select_layou, null);

            holder = new ViewHolder();

            holder.text = (TextView) convertView.findViewById(R.id.label);
            holder.checkbox = (CheckBox) convertView.findViewById(R.id.check);
                    convertView.setTag(holder);
            holder.checkBox.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    CheckBox cb = (CheckBox) v;
                    MultiSelectItem element = (MultiSelectItem) cb.getTag();
                    element .setSelected(cb.isChecked());
                }
            });
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.text.setText(list.get(position).getName());
        holder.checkbox.setChecked(list.get(position).isSelected());
        holder.checkBox.setTag(list.get(position));
        return convertView ;
    }
}

Answer 2

I ended up making these edits to the code:

Added this to the end of the adapter as 3 more methods

public int getCount() {
        return list.size();
    }

    public MultiSelectItem getItem(int position) {
        return list.get(position);
    }
    public long getItemId(int position) {
        return 0;
    }

Then added this to my activity: (in the button)

List<MultiSelectItem> checkedData = adapter.list;
            Log.e("string results", "string results " + getMultiSelectItem().size());
            for(MultiSelectItem item :checkedData) {
                if(item.isSelected()) {
                    Log.e("checker", item.getName());
                }
            }

and this minor change to the adapter on top:

//adapter with custom model
    private MultiSelectAdapter adapter;