Does anyone know how to highlight a selected item

2020-07-26 10:36发布

问题:

I'm trying to create a listview where upon tapping an item the background changes color. So far my current implementation results in the "opposite" visible cell having its background changed. For example, if I chose the top item in the list, the bottom item is highlighted. Can anyone help me implement the desired functionality?

My list Activity:

        public void onCreate(Bundle savedInstanceState) {

    Log.e(TAG, "Starting Symptom Activity...");
    super.onCreate(savedInstanceState);


    setContentView(R.layout.symptom_listview);
    // Setup list
    this.setupSymptomScreen();
    startManagingCursor(cs);
    //get handle on buttons
    Button nextButton = (Button) findViewById(R.id.symptom_next);
    Button backButton = (Button) findViewById(R.id.symptom_goBack);
    ListView lv =getListView();

    lv.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
    lv.setItemsCanFocus(false);

    SymptomAdapter adapter = new SymptomAdapter(this,
            R.layout.symptom_item, cs, new String[] { DbAdapter.KEY_SYMPTOM },
            new int[] { R.id.txt_symptom });

    selectedItems = new HashSet<String>();
    adapter.setLookupTable(selectedItems);
    setListAdapter(adapter);



    lv.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,
            int position, long id) {
        if(!selectedItems.contains(view.toString()))
        {
            view.setBackgroundColor(Color.CYAN);
            String symptom = ((TextView) view.findViewById(R.id.txt_symptom)).getText().toString();
            selectedItems.add(symptom);

        }
        else
        {
            view.setBackgroundColor(Color.WHITE);
            selectedItems.remove(view.toString());
        }


                    }
      });
          nextButton.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View v) {
            // import selected items into a list
            importSelected();
            // figure out category
            process();
        }
    });
    //List for symptom ids
    symptoms_id = new ArrayList<Integer>(cs.getCount());

}

And I also have made my own adapter in which I have overridden getView

    public View getView(int position, View convertView, ViewGroup parent) {

        if(convertView != null){
            String symptoms = ((TextView) convertView.findViewById(R.id.txt_symptom)).getText().toString();
            if(!selectedItems.contains(symptoms))
                convertView.setBackgroundColor(Color.WHITE);
            }

            return super.getView(position, convertView, parent);
    }

回答1:

Here is an example:

private class ItemAdapter extends SimpleAdapter {

    private int mItemIndex = -1; 

    public ItemAdapter(Context context,
        List<? extends Map<String, ?>> data, int resource,
        String[] from, int[] to) {
        super(context, data, resource, from, to);
        // TODO Auto-generated constructor stub
    }

    /* (non-Javadoc)
     * @see android.widget.SimpleAdapter#getView(int, android.view.View, android.view.ViewGroup)
     */
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        View view = super.getView(position, convertView, parent);
        if (position == mItemIndex) {
            convertView.setSelected(true);
            convertView.setPressed(true);
            convertView.setBackgroundColor(Color.parseColor("#FF9912"));
        }

        return view;
    }

    public void setSelectItem(int index) {
        mItemIndex = index;
    }

    public int getSelectItem() {
        return mItemIndex;
    }

}

When you select an item, the onItemClick function is like:

public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
    ((ItemAdapter)list.getAdapter()).setSelectItem(arg2);
}