android - 如何在可扩展 ListView android中将 child 添加到特定的 parent

Question

我创建了一个应用程序，在该应用程序中，我通过设置 10 的限制从 sqlite 加载了数据，当列表向下滚动时，它使用异步任务从 sqlite 加载了另外 10 个数据，在这部分我已经获取了标题组作为以及子数据，但我不知道如何为新日期放置一个 child ，谁能告诉我如何在可扩展 ListView 中将一个 child 添加到特定父对象

异步任务:

 class LoadDataTask extends AsyncTask<String, Void, String> {
    ArrayList<Daybook> daybooks1 = new ArrayList<Daybook>();

    @Override
    protected String doInBackground(String... olimits) {
        String limits = null;

        loadingMore = true;
        try {
            limits = olimits[0];
            grouplistDataHeader = new ArrayList<String>();
            grouplistDataChild = new HashMap<String, List<Daybooklist>>();
            groupdaybooklists = new ArrayList<Daybooklist>();

            databasehandler = new DatabaseHandler(getApplicationContext());
            loadeddate = new ArrayList<String>();
            String selectquery = "SELECT date,IFNULL(SUM(amountin),0) as amountin,IFNULL(SUM(amountout),0),daybookusertype as amountout FROM daybookdetails GROUP BY strftime('%Y-%m-%d',date) ORDER BY strftime('%Y-%m-%d',date) DESC LIMIT 11,20";
            SQLiteDatabase db = databasehandler.getReadableDatabase();
            Cursor cursor = db.rawQuery(selectquery, null);
            if (cursor.moveToFirst()) {
                do {
                    loadeddate.add(cursor.getString(0));
                    for (String s : loadeddate) {
                        newdate = s;

                    }
                    String[] spiliter = newdate.split("-");
                    String year = spiliter[0];
                    String month = spiliter[1];
                    String dates = spiliter[2];
                    if (month.startsWith("01")) {
                        disorderedlist = dates + "Jan" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("02")) {
                        disorderedlist = dates + "Feb" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("03")) {
                        disorderedlist = dates + "Mar" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("04")) {
                        disorderedlist = dates + "Apr" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("05")) {
                        disorderedlist = dates + "May" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("06")) {
                        disorderedlist = dates + "Jun" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("07")) {
                        disorderedlist = dates + "Jul" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("08")) {
                        disorderedlist = dates + "Aug" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("09")) {
                        disorderedlist = dates + "Sep" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("10")) {
                        disorderedlist = dates + "Oct" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("11")) {
                        disorderedlist = dates + "Nov" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    } else if (month.startsWith("12")) {
                        disorderedlist = dates + "Dec" + year;
                        disorderedlist = disorderedlist.replaceAll("\\s+", "");
                    }
                    for (int i = 0; i < daybooks1.size(); i++) {
                        listDataHeader.add(disorderedlist);
                        groupdaybooklists = databaseHandler.getAllDaywisedaybookdetails(newdate);
                        for (int j = 0; j < groupdaybooklists.size(); j++) {
                            String name = groupdaybooklists.get(j).getName();
                            String desc = groupdaybooklists.get(j).getDescription();
                            String type = groupdaybooklists.get(j).getType();
                            String usertype = groupdaybooklists.get(j).getUsertype();
                            String amtin = groupdaybooklists.get(j).getAmountin();
                            String amtout = groupdaybooklists.get(j).getAmountout();
                            String extamt = groupdaybooklists.get(j).getExtraamt();
                            String mobno = groupdaybooklists.get(j).getMobileno();
                            String datess = groupdaybooklists.get(j).getSdate();
                            String time = groupdaybooklists.get(j).getCtime();
                            chid.add(new Daybooklist(name, desc, type, usertype, amtin, amtout, extamt, mobno, datess, time));

                        }

                        listDataChild.put(listDataHeader.get(i), chid);

                    }



                } while (cursor.moveToNext());

            }


            cursor.close();
            db.close();
        } catch (Exception e) {
            e.printStackTrace();
        }


        return disorderedlist;
    }

    @Override
    protected void onPostExecute(String disorderedlist) {



        listAdapter.notifyDataSetChanged();
        loadingMore = false;

    }

我感到困惑的部分:

 @Override
protected String doInBackground(String... olimits) {
    String limits = null;

    loadingMore = true;
    try {
        limits = olimits[0];
        grouplistDataHeader = new ArrayList<String>();
        grouplistDataChild = new HashMap<String, List<Daybooklist>>();
        groupdaybooklists = new ArrayList<Daybooklist>();

        databasehandler = new DatabaseHandler(getApplicationContext());
        loadeddate = new ArrayList<String>();
        String selectquery = "SELECT date,IFNULL(SUM(amountin),0) as amountin,IFNULL(SUM(amountout),0),daybookusertype as amountout FROM daybookdetails GROUP BY strftime('%Y-%m-%d',date) ORDER BY strftime('%Y-%m-%d',date) DESC LIMIT 11,20";
        SQLiteDatabase db = databasehandler.getReadableDatabase();
        Cursor cursor = db.rawQuery(selectquery, null);
        if (cursor.moveToFirst()) {
            do {
                loadeddate.add(cursor.getString(0));
                for (String s : loadeddate) {
                    newdate = s;

                }
                String[] spiliter = newdate.split("-");
                String year = spiliter[0];
                String month = spiliter[1];
                String dates = spiliter[2];
                if (month.startsWith("01")) {
                    disorderedlist = dates + "Jan" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("02")) {
                    disorderedlist = dates + "Feb" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("03")) {
                    disorderedlist = dates + "Mar" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("04")) {
                    disorderedlist = dates + "Apr" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("05")) {
                    disorderedlist = dates + "May" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("06")) {
                    disorderedlist = dates + "Jun" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("07")) {
                    disorderedlist = dates + "Jul" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("08")) {
                    disorderedlist = dates + "Aug" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("09")) {
                    disorderedlist = dates + "Sep" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("10")) {
                    disorderedlist = dates + "Oct" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("11")) {
                    disorderedlist = dates + "Nov" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                } else if (month.startsWith("12")) {
                    disorderedlist = dates + "Dec" + year;
                    disorderedlist = disorderedlist.replaceAll("\\s+", "");
                }
                for (int i = 0; i < daybooks1.size(); i++) {
                    listDataHeader.add(disorderedlist);
                    groupdaybooklists = databaseHandler.getAllDaywisedaybookdetails(newdate);
                    for (int j = 0; j < groupdaybooklists.size(); j++) {
                        String name = groupdaybooklists.get(j).getName();
                        String desc = groupdaybooklists.get(j).getDescription();
                        String type = groupdaybooklists.get(j).getType();
                        String usertype = groupdaybooklists.get(j).getUsertype();
                        String amtin = groupdaybooklists.get(j).getAmountin();
                        String amtout = groupdaybooklists.get(j).getAmountout();
                        String extamt = groupdaybooklists.get(j).getExtraamt();
                        String mobno = groupdaybooklists.get(j).getMobileno();
                        String datess = groupdaybooklists.get(j).getSdate();
                        String time = groupdaybooklists.get(j).getCtime();
                        chid.add(new Daybooklist(name, desc, type, usertype, amtin, amtout, extamt, mobno, datess, time));

                    }

                    listDataChild.put(listDataHeader.get(i), chid);

                }



            } while (cursor.moveToNext());

        }


        cursor.close();
        db.close();
    } catch (Exception e) {
        e.printStackTrace();
    }


    return disorderedlist;
}

Answer 1

需要在onCreate方法中初始化listView的adapter:

listView.setAdapter(adapter); // Pode ser com as listas vazias

之后，在后台方法中，你只需要加载数据并保存在一些类属性中。之后，在onPostResult方法中，需要更新adapter并通知listView:

protected void onPostExecute(String disorderedlist) {
    adapter.addGroupList(groupList); // Need to implement the method in the adapter
    adapter.addChildList(childList); // Need to implement the method in the adapter
    adapter.notifyDataSetChanged();
    loadingMore = false;
}

思路是这样的，换个逻辑。