Question

我有一个使用CursorAdapter的ListActivity，我无法刷新它。以下是我使用的一些代码：

public class ContactDetailsActivity extends ListActivity
{

    private ContactDetailsBroadcastReceiver mLvBroadcastReceiver;
    private Contact contact;


    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);


        contact = (Contact)getIntent().getSerializableExtra(AwesomeApp.CONTACT_OBJECT);

        if(contact == null) {
            DataUtils.log("Starting ContactDetailsActivity with NULL contact.");
            Toast.makeText(this, getString(R.string.no_contact_selected), Toast.LENGTH_SHORT).show();
            finish();
            return;
        }

        DataUtils.log("Starting ContactDetailsActivity with contact:" + contact.toString());
        setTitle(contact.getName());

        Cursor cursor = getContactDetailsCursor();
        startManagingCursor(cursor);

        setListAdapter(new ContactDetailsCursorAdapter(this, cursor));

        ListView lv = getListView();
        lv.setBackgroundResource(R.color.white);
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener()
        {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id)
            {
                Toast.makeText(ContactDetailsActivity.this, "touched", Toast.LENGTH_SHORT).show();
            }
        });

        //Create broadcast receiver, to detect when a file upload has finished so we can update the pic status.
        mLvBroadcastReceiver = new ContactDetailsBroadcastReceiver();
    }

    private class ContactDetailsBroadcastReceiver extends BroadcastReceiver
    {
        @Override
        public void onReceive(Context context, Intent intent)
        {
            DataUtils.log("In BroadcastReceiver - ContactDetails");
            refreshListView();
        }
    }

我的适配器基本上只是扩展CursorAdapter，其中我覆盖了newView和bindView：

public class ContactDetailsCursorAdapter extends CursorAdapter

我在ContactDetailsActivity内部有一个名为refreshListView()的方法，我在onResume()中调用此方法，并在我的BroadcastReceiver的onReceive()方法中

private void refreshListView()
{
    DataUtils.log("In ContactDetailsActivity refreshListView");
    ((ContactDetailsCursorAdapter)getListAdapter()).notifyDataSetChanged();

    this.getListView().invalidate();

    this.getListView().invalidateViews();
}

这是我的getContactDetailsCursor()方法：

private Cursor getContactDetailsCursor()
{
    AwesomeDbAdapter dbAdapter = AwesomeApp.getDbAdapter(this);
    Cursor c = dbAdapter.getRecentConversationsFromContact(contact.getId());
    DataUtils.log("New ContactDetails cursor has " + c.getCount() + " elements");
    return c;
}

正如您所看到的，我们已经尝试了notifyDataSetChanged()，invalidate()，invalidateViews()，似乎没有任何内容可以刷新列表视图。

我完全没有关于如何刷新它的想法。我看到日志和方法都是从onResume()和BroadcastReceiver的onReceive()方法调用的。

任何指针都表示赞赏！

Answer 1

这最终对我有用。正如@Kirill Shalnov所提到的，startManagingCursor()已被弃用，但这是我需要使用的。说实话，这一切都是猜测，但唉，做了我需要的。

@SuppressWarnings("deprecation")
private void refreshListView()
{
    DataUtils.log("In ContactDetailsActivity refreshListView");

    ContactDetailsCursorAdapter adapter = (ContactDetailsCursorAdapter)getListAdapter();

    Cursor oldCursor = null;
    if(adapter != null) {
        oldCursor = adapter.getCursor();
    }
    Cursor newCursor = getContactDetailsCursor();

    if(oldCursor != null) {
        stopManagingCursor(oldCursor);
        oldCursor.close();
    }
    startManagingCursor(newCursor);

    adapter = null;
    setListAdapter(new ContactDetailsCursorAdapter(this, newCursor));

    ListView listView = getListView();
    listView.setBackgroundResource(R.color.white);
    listView.invalidate();
    listView.invalidateViews();
}

Answer 2

好像你忘了注册接收器了：注册接收器而不注册它不会发射，如下所示注册接收器。

实施例：在OnCreate中：

ContactDetailsBroadcastReceiver receiver=new ContactDetailsBroadcastReceiver();
IntentFilter filter=new IntentFilter("android.net.wifi.STATE_CHANGE")
registerReceiver(receiver, filter);

在OnDestroy中：

unregisterReceiver(receiver);

Answer 3

startManagingCursor（光标）;

使用游标是不推荐使用的方式，你应该使用Loaders，它可以自动重新加载数据

使用CursorAdapter从ListActivity刷新ListView

3 个答案: