当我删除列表中的项目时，我正在尝试刷新我的视图。我目前正在尝试刷新/重新加载AsyncTask的onPostExecute方法中的视图。到目前为止，我没有尝试过任何工作。这似乎是一项容易完成的任务。我的自定义适配器扩展了BaseAdapter。我希望有一些简单的我想念。任何人都可以光明吗？
干杯。
public class ItemListActivity extends OrmLiteBaseListActivity<DatabaseHelper> {
private final String TAG = getClass().getSimpleName();
private DatabaseHelper dbHelper;
private ListView itemListView;
private ItemListAdapter listAdapter;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.itemslistactivity);
registerForContextMenu(getListView());
itemListView = getListView();
itemListView.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.listview_context_menu, menu);
}
});
listAdapter = new ItemListAdapter(getApplicationContext(), new ArrayList<Item>());
itemListView.setAdapter(listAdapter);
dbHelper = getHelper();
new SelectDataTask().execute(dbHelper);
}
public void add_OnClick(View v) {
Intent intent = new Intent();
intent.setClass(this, AddItemActivity.class);
startActivity(intent);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
Item b = (Item) listAdapter.getItem(info.position);
try {
switch (item.getItemId()) {
case R.id.remove_item:
dbHelper.getItemDao().deleteById(new Integer(b.id));
listAdapter.notifyDataSetChanged();
return true;
}
} catch (SQLException e) {
//FIXME
e.printStackTrace();
Log.e(TAG, e.getMessage());
}
return false;
}
private class SelectDataTask extends AsyncTask<DatabaseHelper, Void, List<Item>> {
private final ProgressDialog dialog = new ProgressDialog(
ItemListActivity.this);
// can use UI thread here
protected void onPreExecute() {
this.dialog.setMessage("Retreiving item data...");
this.dialog.show();
}
@Override
protected List<Item> doInBackground(DatabaseHelper... params) {
List<Item> l = null;
try {
Dao<Item, Integer> dao = params[0].getItemDao();
l = dao.queryForAll();
} catch (SQLException e) {
//TODO -- cleanup
e.printStackTrace();
Log.e(TAG, e.getMessage());
}
return l;
}
// can use UI thread here
@Override
protected void onPostExecute(List<Item> b) {
listAdapter = new MyListAdapter(getApplicationContext(), b);
itemListView.setAdapter(listAdapter);
//TODO -- none of this works
itemListView.invalidateViews();
listAdapter.notifyDataSetChanged();
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
}
}
答案 0 :(得分：0)
检查我的解决方案（组CRUD）：
public class GroupsPreferenceActivity extends BaseAppActivity {
private DatabaseHelper dbHelper;
private ListView listView;
private GroupAdapter groupAdapter;
private DatabaseModel groupModel;
private OnDeleteListener onDeleteListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.group_preference_layout);
setDbHelper(new DatabaseHelper(getApplicationContext()));
setGroupModel(new DatabaseModel(getDbHelper(), GroupData.class));
setListView((ListView) findViewById(R.id.lv_group));
setGroupAdapter(new GroupAdapter(GroupsPreferenceActivity.this));
getListView().setAdapter(getGroupAdapter());
setOnDeleteListener(new OnDeleteListener() {
@Override
public void onClick(GroupData group) {
removeGroup(group);
}
});
getListView().setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapter, View parent,
int position, long id) {
addGroup(getGroupAdapter().getItem(position));
}
});
getGroupAdapter().setOnDeleteListener(getOnDeleteListener());
doLoadGroups();
}
private void doLoadGroups() {
getGroupAdapter().clear();
List<?> items = getGroupModel().getAll();
for (Object group : items) {
getGroupAdapter().add((GroupData) group);
}
getGroupAdapter().notifyDataSetChanged();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getSupportMenuInflater().inflate(R.menu.groups_preference_menu, menu);
return true;
}
@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
super.onMenuItemSelected(featureId, item);
switch (item.getItemId()) {
case R.id.option_item_add_group:
addGroup();
break;
default:
break;
}
return true;
}
private void addGroup() {
addGroup(null);
}
private void addGroup(final GroupData groupData) {
LayoutInflater factory = LayoutInflater
.from(GroupsPreferenceActivity.this);
final View textEntryView = factory.inflate(
R.layout.create_group_dialog_view, null);
final EditText editName = (EditText) textEntryView
.findViewById(R.id.tv_group_name);
String positiveButtonName = getString(R.string.create);
OnClickListener positiveListener = new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
createGroup(editName.getText().toString());
}
};
if (groupData != null) {
positiveButtonName = getString(R.string.update);
editName.setText(groupData.getName());
positiveListener = new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
groupData.setName(editName.getText().toString());
updateGroup(groupData);
}
};
}
AlertDialog.Builder builder = new AlertDialog.Builder(
GroupsPreferenceActivity.this);
String title = getString(R.string.preference_add_group);
builder.setCancelable(true)
.setTitle(title)
.setView(textEntryView)
.setPositiveButton(positiveButtonName, positiveListener)
.setNegativeButton(getString(R.string.cancel),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
final AlertDialog alert = builder.create();
alert.show();
final Button yesButton = alert.getButton(Dialog.BUTTON_POSITIVE);
yesButton.setEnabled(false);
editName.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
@Override
public void afterTextChanged(Editable s) {
yesButton.setEnabled(s.length() > 0);
}
});
}
protected void updateGroup(GroupData groupData) {
getGroupModel().update(groupData);
doLoadGroups();
}
protected void createGroup(String name) {
GroupData groupData = new GroupData();
groupData.setName(name);
getGroupModel().add(groupData);
doLoadGroups();
}
protected void removeGroup(GroupData group) {
getGroupModel().remove(group);
doLoadGroups();
}
public DatabaseHelper getDbHelper() {
return dbHelper;
}
public void setDbHelper(DatabaseHelper dbHelper) {
this.dbHelper = dbHelper;
}
public ListView getListView() {
return listView;
}
public void setListView(ListView listView) {
this.listView = listView;
}
public GroupAdapter getGroupAdapter() {
return groupAdapter;
}
public void setGroupAdapter(GroupAdapter groupAdapter) {
this.groupAdapter = groupAdapter;
}
public DatabaseModel getGroupModel() {
return groupModel;
}
public void setGroupModel(DatabaseModel groupModel) {
this.groupModel = groupModel;
}
public OnDeleteListener getOnDeleteListener() {
return onDeleteListener;
}
public void setOnDeleteListener(OnDeleteListener onDeleteListener) {
this.onDeleteListener = onDeleteListener;
}
}
我的数据库帮助者位于：https://github.com/beshkenadze/android-utils/tree/master/src/net/beshkenadze/android/db