我的项目是todo 我有4个选项卡，4个片段和4个列表（操作栏导航包含4个选项卡和ViewPager）。 4 list（tab）使用相同的db表，但每个都使用categoryID检索不同的数据。 我为所有这些使用Asynctask，读取数据并将适配器设置为列表。
public class AsyncTaskDB extends AsyncTask<Void, Void, listAdapter> {
Context act;
int Categoryid;
ArrayList<memo> arraymemo;
listAdapter myadapter;
ListView list;
listAdapter listAdp;
public AsyncTaskDB(Context acti, int categoryID) {
this.act = acti;
this.Categoryid = categoryID;
}
@Override
protected listAdapter doInBackground(Void... params) {
MemoDBHelper helper = new MemoDBHelper(act);
// getAllDataByCategoryID
if (Categoryid != CategoryID.Done_ID)
arraymemo = helper.getAllTaskByCategory(Categoryid);
else
arraymemo = (ArrayList<memo>) helper.gatDoneMemo();
myadapter = new listAdapter(act, arraymemo);
if (myadapter == null) {
Toast.makeText(act, "no data", Toast.LENGTH_SHORT).show();
cancel(true);
}
return myadapter;
}
@Override
protected void onPostExecute(listAdapter result) {
switch (Categoryid) {
case CategoryID.Urgent_Imprtant_ID:
list = (ListView) ((Activity) act)
.findViewById(R.id.Urgent_Important_list);
break;
case CategoryID.Urgent_Less_Imprtant_ID:
list = (ListView) ((Activity) act)
.findViewById(R.id.Urgent_Less_Important_list);
break;
case CategoryID.Less_Urgent_Imprtant_ID:
list = (ListView) ((Activity) act)
.findViewById(R.id.Less_Urgent_Imprtant_list);
break;
case CategoryID.Neither_Urgent_Or_Imprtant_ID:
list = (ListView) ((Activity) act)
.findViewById(R.id.Neither_Urgent_Imprtant_list);
break;
case CategoryID.Done_ID:
list = (ListView) ((Activity) act).findViewById(R.id.ArchiveList);
break;
}
list.setAdapter(result);
this.listAdp = result;
}
public listAdapter getlistAdapter() {
return this.listAdp;
}
}
列表中的每个备忘录都有Done CheckBox。当用户检查并取消选中它时，自动备忘录更新db。（在自定义适配器中）
----------------------------
| -- |
| | | memotitle |
| -- |
----------------------------
public class listAdapter extends BaseAdapter implements OnCheckedChangeListener { Context act;
ArrayList<memo> MemoArray;
SparseBooleanArray mcheck;
int pos;
MemoDBHelper helper;
public listAdapter(Context activity, ArrayList<memo> memoarray) {
this.act = activity;
this.MemoArray = memoarray;
mcheck = new SparseBooleanArray(memoarray.size());
helper = new MemoDBHelper(act);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return MemoArray.size();
}
@Override
public memo getItem(int position) {
// TODO Auto-generated method stub
return MemoArray.get(position);
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return 0;
}
public class viewHolder {
TextView title;
// TextView description;
CheckBox chkstatus;
}
viewHolder it;
@Override
public View getView(int position, View convertView, ViewGroup parent) {
pos = position;
LayoutInflater in = ((Activity) act).getLayoutInflater();
if (convertView == null) {
convertView = in.inflate(R.layout.list_item, null);
it = new viewHolder();
it.title = (TextView) convertView.findViewById(R.id.txt_list_title);
it.chkstatus = (CheckBox) convertView
.findViewById(R.id.chkStatusid);
convertView.setTag(it);
} else {
it = (viewHolder) convertView.getTag();
}
it.title.setText(MemoArray.get(position).GetTitle());
it.chkstatus.setChecked(MemoArray.get(position).GetSattus());
it.chkstatus.setOnCheckedChangeListener(this);
it.chkstatus.setTag(String.valueOf(MemoArray.get(position).GetID()));
return convertView;
}
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
mcheck.put(Integer.valueOf((String) buttonView.getTag()), isChecked);
helper.updateStatusByID(Integer.valueOf((String) buttonView.getTag()),
(isChecked));
helper.close();
//after db updatedt ,call method in fragment to notifydatsetchanged!
UrgentImportant_frg.notifyAdapter();
}
}
适配器必须通知已更改的数据，并且列表不显示已完成的备忘录。我不知道如何操作！ 我的第一个片段：
public class UrgentImportant_frg extends Fragment {
static listAdapter myadp;
ListView list;
// memo selectedmemo;
long[] checkid;
AsyncTaskDB asyn;
ArrayList<memo> selectedMemoArray;
final static int RQS_MoveTo = 10;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootview = inflater.inflate(R.layout.urgentimportant_layout,
container, false);
return rootview;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
list.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
selectedMemoArray = new ArrayList<memo>();
list.setMultiChoiceModeListener(new MultiChoiceModeListener() {
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return true;
}
@Override
public void onDestroyActionMode(ActionMode mode) {
// list.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
}
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
mode.getMenuInflater().inflate(R.menu.list_select_menu, menu);
/*
* MenuInflater inflater = getActivity().getMenuInflater();
* inflater.inflate(R.menu.list_select_menu, menu);
*/
mode.setTitle("Select Items");
return true;
}
@Override
public boolean onActionItemClicked(final ActionMode mode,
MenuItem item) {
switch (item.getItemId()) {
case R.id.deletemenu:
final int[] myitemsid = getSelectedID();
final MemoDBHelper helper = new MemoDBHelper(getActivity());
AlertDialog.Builder myAlert = new AlertDialog.Builder(
getActivity());
myAlert.setMessage(
"Are you sure to delete " + myitemsid.length
+ " memo ?")
.setPositiveButton("yes", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
for (int j = 0; j < myitemsid.length; j++) {
helper.deleteRow(myitemsid[j]);
/*
* if (j == myitemsid.length - 1) {
* strid[j] = String
* .valueOf(myitemsid[j]); } else {
* strid[j] = String
* .valueOf(myitemsid[j]) + ","; }
*/
}
mode.finish();
onResume();
}
}).setNegativeButton("no", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
mode.finish();
}
});
AlertDialog alert = myAlert.create();
alert.show();
// mode.finish();
break;
case R.id.MoveTomenu:
// myadp.getItem(position);
Intent i = new Intent(getActivity(),
MoveToCategory_act.class);
i.putExtra("categoryid", CategoryID.Urgent_Imprtant_ID);
startActivityForResult(i, RQS_MoveTo);
mode.finish();
break;
}
return true;
}
// get selected id to delete and move category
@Override
public void onItemCheckedStateChanged(ActionMode mode,
int position, long id, boolean checked) {
if (myadp == null) {
myadp = asyn.getlistAdapter();
}
int p = ifMemoSelectedBefore(myadp.getItem(position));
if (p != -1) {
selectedMemoArray.remove(p);
} else if (checked) {
selectedMemoArray.add(myadp.getItem(position));
}
final int checkedCount = list.getCheckedItemCount();
switch (checkedCount) {
case 0:
mode.setSubtitle(null);
break;
case 1:
mode.setSubtitle("One Item Selected");
break;
default:
mode.setSubtitle(checkedCount + " Item Selected");
break;
}
}
});
getActivity().getActionBar().setSubtitle("subtitle");
}
public int ifMemoSelectedBefore(memo m) {
return selectedMemoArray.indexOf(m);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onViewCreated(view, savedInstanceState);
list = (ListView) view.findViewById(R.id.Urgent_Important_list);
// -------------click item
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
if (myadp == null) {
myadp = asyn.getlistAdapter();
}
// Log.d("tag", myadp.getItem(position).GetTitle() + "");
Intent nextintent = new Intent(getActivity(),
EditMemo_act.class);
memo g = myadp.getItem(position);
/*
* MemoDBHelper helper = new MemoDBHelper(getActivity());
* helper.updateStatusByID(g.GetID(), true);
*/
nextintent.putExtra("editmemo", g);
startActivity(nextintent);
}
});
}
@Override
public void onResume() {
asyn = new AsyncTaskDB(getActivity(), CategoryID.Urgent_Imprtant_ID);
asyn.execute();
super.onResume();
}
public int[] getSelectedID() {
int[] SelectedArray_ID = new int[selectedMemoArray.size()];
for (int j = 0; j < selectedMemoArray.size(); j++) {
SelectedArray_ID[j] = selectedMemoArray.get(j).GetID();
// Log.d("id", selectedMemoArray.get(j).GetID() + "");
}
return SelectedArray_ID;
}
// -------------一个通知myadpter的方法 public static void notifyAdapter（）{ if（myadp！= null）{ myadp.notifyDataSetChanged（）; Log.d（＆＃34; notify＆＃34;，＆＃34; here＆＃34;）; }
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == RQS_MoveTo) {
if (resultCode == Result.RESULT_OK) {
int id = data.getExtras().getInt("NEWCategoryID");
MemoDBHelper helper = new MemoDBHelper(getActivity());
final int[] myitemsid = getSelectedID();
for (int j = 0; j < myitemsid.length; j++) {
helper.updateCategory(myitemsid[j], id);
}
onResume();
}
}
}
}
在适配器更改后是否有片段中的任何方法运行？或者在myadapter中，db更新后我调用片段中的方法来通知数据已更改？我认为第二种解决方案并非正确＆gt; _＆lt;
p.s：notifyAdapter（）不起作用，是因为我的适配器填写了asyntask吗？
答案 0 :(得分：1)
当适配器发生变化时，请尝试调用以下方法。
使用FragmentPagerAdapter或ListView后，当您更改数据时，应该调用它。
notifyDataSetChanged();