Question

例如,我为我的安有机器人应用程序参考了几个例子。在列表活动中,在 < 强/ 强 > 方法之前的 < 强/ 强 > 方法之前,“ 强/强” 数组被预先定义为:

String[] items = new String[]{"Text for Item1", "text for item2", ....};

在 < 坚固 > 创建 < / 坚固 > 方法中,我使用最简单的方法设置适配器,并显示以下列表视图:

setListAdapter( new ArrayAdapter<String>(this,
 android.R.layout.simple_list_item_checked, items));

我已经推翻了这个方法:

@Override    
 protected void onListItemClick(ListView l, View v, int position, long id)    
{     
     CheckedTextView textview = (CheckedTextView)v;
     textview.setChecked(!textview.isChecked());
}

上述所有代码都正常工作。 ListSView 中每个诉讼人的检查标记可以手动显示和设置检查/未检查。

MY PROBLEM IS: I want to set some items by program,not by hand clicking, to be checked/unchecked and the checkmark be changed along too. Can it be done and how to do it ?

感谢前台的帮助

Answer 1

我认为Google的Romain Guy在这可以解决你的问题:

Actually you want to use CheckedTextView with choiceMode. That s what
CheckedTextView is for. However, you should not be calling setChecked
from bindView(), but let ListView handle it. The problem was that you
were doing ListView s job a second time. You don t need listeners
(click on onlistitem), calls to setChecked, etc.

以下是我对此的解决方案:

class MyActivity extends ListActivity { // or ListFragment

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // some initialize

        new UpdateCheckedTask().execute(); // call after setListAdapter
    }

    // some implementation

    class UpdateChecked extends AsyncTask<Void, Void, List<Integer>> {

        @Override
        protected List<Integer> doInBackground(Void... params) {
            ListAdapter listAdapter = getListAdapter();
            if (listAdapter == null) {
                return null;
            }

            List<Integer> positionList = new ArrayList<Integer>();
            for (int position = 0; position < listAdapter.getCount(); position++) {
                Item item = (Cursor) listAdapter.getItem(position); // or cursor, depends on your ListAdapter implementaiton
                boolean checked = item.isChecked() // your model
                positionList.add(position, checked);
            }
            return positionList;
        }

        @Override
        protected void onPostExecute(List<Integer> result) { // setItemChecked in UI thread
            if (result == null) {
                return;
            }

            ListView listView = getListView();
            for (Iterator<Integer> iterator = result.iterator(); iterator.hasNext();) {
                Integer position = iterator.next();
                listView.setItemChecked(position, true);
            }
        }
    }
}

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