Blackberry - get checked items from list with checkboxes

问题

How can all checked items from a list can be fetched?

I need to get all selected (checked) items from the list and populate a vector.

I am not getting all selected items, I am getting only the item on which current focus is.

I am implementing listfield with checkboxes as per the knowledgebase article.

If I use getSelection(), it is returning me the currently highlighted list row index, and not all that have been checked.

回答1:

As I undestood, sample is How To - Create a ListField with check boxes

Then you can add Vector to the class where ListFieldCallback is implemented:

private Vector _checkedData = new Vector();
public Vector getCheckedItems() {
        return _checkedData;
    }

and update drawListRow this way:

if (currentRow.isChecked())
{
    if( -1 ==_checkedData.indexOf(currentRow))
        _checkedData.addElement(currentRow);
    rowString.append(Characters.BALLOT_BOX_WITH_CHECK);
}
else
{
    if( -1 !=_checkedData.indexOf(currentRow))
        _checkedData.removeElement(currentRow);
    rowString.append(Characters.BALLOT_BOX);
}

---

If you would use VerticalFieldManager with custom CheckBoxField, you could iterate over all fields on screen (or any manager) and check if its' checkbox field, then take a value:

class List extends VerticalFieldManager {
...
    public Vector getCheckedItems() {
        Vector result = new Vector();
        for (int i = 0, cnt = getFieldCount(); i < cnt; i++) {
            Field field = getField(i);
            if (field instanceof CheckboxField) {
                CheckboxField checkboxField = (CheckboxField) field;
                if (checkboxField.isChecked())
                    result.addElement(checkboxField);
            }
        }
        return result;
    }
}

回答2:

@sandhya-m

class List extends VerticalFieldManager {
...
    public void selectAll() {
        for (int i = 0, cnt = getFieldCount(); i < cnt; i++) {
                Field field = getField(i);
                if (field instanceof CheckboxField) {
                        CheckboxField checkboxField = (CheckboxField) field;
                        checkboxField.setChecked(true);
                }
        }
    }
}

来源：https://stackoverflow.com/questions/1186383/blackberry-get-checked-items-from-list-with-checkboxes