Android 将新 Cursor 设置为 listView

Question

当用户在 EditText 中输入字母时，我在将新的 Adapter 设置为 listView 时遇到了一些问题。所以我正在做的事情是，当我的 Activity 第一次启动时，我使用游标和自定义适配器从数据库填充 listView。当用户在 EditText 中输入一些文本时，我正在创建新的 sql 语句并使用新的 Cursor 获取数据。之后，我创建新的自定义适配器并尝试将其设置到我的列表视图。

问题是，当我开始输入编辑文本时，我可以在 LogCat 的日志中看到 sql 语句和光标大小是正确的，但我的 ListView 没有填充新数据。它保持不变。这是我的做法：

这是我第一次填充 listView 的方式：

cursor = userDbHelper.executeSQLQuery(sqlQuery);

        if (cursor.getCount() == 0) {
            noCards.setVisibility(View.VISIBLE);
            noCards.setText(getString(R.string.no_cards));
        } else if (cursor.getCount() > 0) {
            noCards.setVisibility(View.GONE);
                for (cursor.move(0); cursor.moveToNext(); cursor.isAfterLast()) {
                    objectId = Integer.parseInt(cursor.getString(cursor.getColumnIndex("objectId")));
                    cardId.add(objectId);

                    title = cursor.getString(cursor.getColumnIndex("title"));
                    catTitle = cursor.getString(cursor.getColumnIndex("catTitle"));
                    int repeats = Integer.parseInt(cursor.getString(cursor.getColumnIndex("repeatsCount")));
                    count.add(repeats);

                    if(extra != 0){
                                String cardsm = "SELECT objectId FROM cardmedias "
                                                + "WHERE cardId="
                                                + objectId
                                                + " AND mediaType=" 
                                                + 5012;

                                Cursor cardsM = userDbHelper.executeSQLQuery(cardsm);
                                if (cardsM.getCount() == 0) {


                                } else if (cardsM.getCount() > 0) {
                                    for (cardsM.move(0); cardsM.moveToNext(); cardsM.isAfterLast()) {
                                        objectID = Integer.parseInt(cardsM.getString(cardsM.getColumnIndex("objectId")));

                                        String filename = "mediacard-"+objectID;
                                        if(storageID==1){
                                            path = RPCCommunicator.getImagePathFromInternalStorage(servername, userId, filename, this);
                                        } else if(storageID==2){
                                            path = RPCCommunicator.getImagePathFromExternalStorage(servername, userId, filename);
                                        }
                                        hm.put(objectID, path);

                                        path = hm.get(objectID);
                                        Log.i("","path : "+path);
                                        paths.add(path);
                                        names.add(title);
                                        categories.add(catTitle);
                                    }
                                }
                    } else if (extra==0){
                        names.add(title);
                        categories.add(catTitle);
                    }
                }
        }
        cursor.close();
        adapter = new LazyAdapter(this, paths, names, categories, count);
        listView.setAdapter(adapter);

这就是我使用 TextWatcher 创建新游标和适配器的方式：

searchString = "";
    sqlQuery = getSqlQuery(sort, collId, ascDesc,searchString);

    searchBar.addTextChangedListener(new TextWatcher() {
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        public void afterTextChanged(Editable s) {
            check = 1;
            listView.setAdapter(null);
            searchString = s.toString();
            Log.e("","searchString : "+searchString);
            sqlQuery = getSqlQuery(sort, collId, ascDesc,searchString);
            Log.e(""," sqlquery : "+sqlQuery);
            Cursor cursor = userDbHelper.executeSQLQuery(sqlQuery);
            Log.e("","cursor count : "+cursor.getCount());
            if (cursor.getCount() == 0) {
                noCards.setVisibility(View.VISIBLE);
                noCards.setText(getString(R.string.no_cards));
            } else if (cursor.getCount() > 0) {
                noCards.setVisibility(View.GONE);
                    for (cursor.move(0); cursor.moveToNext(); cursor.isAfterLast()) {
                        objectId = Integer.parseInt(cursor.getString(cursor.getColumnIndex("objectId")));
                        cardId.add(objectId);

                        title = cursor.getString(cursor.getColumnIndex("title"));
                        catTitle = cursor.getString(cursor.getColumnIndex("catTitle"));
                        int repeats = Integer.parseInt(cursor.getString(cursor.getColumnIndex("repeatsCount")));
                        count.add(repeats);

                        if(extra != 0){
                                    String cardsm = "SELECT objectId FROM cardmedias "
                                                    + "WHERE cardId="
                                                    + objectId
                                                    + " AND mediaType=" 
                                                    + 5012;

                                    Cursor cardsM = userDbHelper.executeSQLQuery(cardsm);
                                    if (cardsM.getCount() == 0) {

                                    } else if (cardsM.getCount() > 0) {
                                        for (cardsM.move(0); cardsM.moveToNext(); cardsM.isAfterLast()) {
                                            objectID = Integer.parseInt(cardsM.getString(cardsM.getColumnIndex("objectId")));

                                            String filename = "mediacard-"+objectID;
                                            if(storageID==1){
                                                path = RPCCommunicator.getImagePathFromInternalStorage(servername, userId, filename, OwnedStampii.this);
                                            } else if(storageID==2){
                                                path = RPCCommunicator.getImagePathFromExternalStorage(servername, userId, filename);
                                            }
                                            hm.put(objectID, path);

                                            path = hm.get(objectID);
                                            Log.i("","path : "+path);
                                            paths.add(path);
                                            names.add(title);
                                            categories.add(catTitle);
                                        }
                                    }
                        } else if (extra==0){
                            names.add(title);
                            categories.add(catTitle);
                        }
                    }
            }
            cursor.close();

            LazyAdapter adapter = new LazyAdapter(OwnedStampii.this, paths, names, categories, count);
            listView.setAdapter(adapter);

        }
    });

所以任何想法如何我使用新适配器刷新列表视图。我已经尝试过 adapter.notifySetDataChanged(); 但它不起作用。

提前致谢！

Answer 1

清除您的数据源，在本例中是路径、名称、类别、计数。
将新结果加载到列表（路径、名称、类别、计数）的数据源中，并将列表适配器设置为空，并调用notifyDataSetChanged。

Answer 2

我解决了这个问题，在我的 afterTextChanged() 中，我只是清除用于存储数据的数组列表并将新数据放入其中。