【问题标题】:CheckBox ListView Mysql复选框列表视图 Mysql
【发布时间】:2018-06-26 18:55:45
【问题描述】:

我用了三天时间尝试使用复选框和 ListView 的过滤器来解决这个问题。

在这段代码中,我第一次选中了复选框,它们与每个选定类别的 ID 一起正确列出,并查看了另一个名为 NovaActivity 的 Activity 的 ID。好的?到目前为止一切顺利。

当我重新打开过滤器活动以使用已列出的过滤器创建一个新的相同未选中复选框时,问题如下,即使它们未标记,它也会继续进入 NovaAcitivty。

前: 第一个过滤器选择 1 和 2;

当我将它发送给另一个时,它会转到 1,2;

第二个过滤器我选择 1 并取消选中复选框 2;

当我将它发送给另一个时,它会转到 1,1,2;

我该如何解决这个问题?

注意:重要的是第二次说我打开过滤器活动已经选中的复选框已经预先标记,因为我将它们写入我的远程 MySQL 数据库并检索它们。

如果我不是很清楚可以随意提问,谢谢你的帮助。

public class MainActivity extends AppCompatActivity {
    Context context;
    ArrayList<Category> array_list;
    FavouriteCategoriesJsonParser categoryJsonParser;
    String categoriesCsv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context = this;
        new asyncTask_getCategories().execute();
    }

    public static class CategoryAdapter extends ArrayAdapter<Category> {
        private final List<Category> list;

        public CategoryAdapter(Context context, int resource, List<Category> list) {
            super(context, resource, list);
            this.list = list;
        }

        static class ViewHolder {
            protected TextView categoryName;
            protected CheckBox categoryCheckBox;
        }

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {

            ViewHolder viewHolder = null;
            if (convertView == null) {
                LayoutInflater inflator = LayoutInflater.from(getContext());
                convertView = inflator.inflate(R.layout.row_category, null);
                viewHolder = new ViewHolder();
                viewHolder.categoryName = (TextView) convertView.findViewById(R.id.row_categoryname_textview);
                viewHolder.categoryCheckBox = (CheckBox) convertView.findViewById(R.id.row_category_checkbox);

                viewHolder.categoryCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

                    @Override
                    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                        int getPosition = (Integer) buttonView.getTag();
                        list.get(getPosition).setSelected(buttonView.isChecked());
                        if (buttonView.isChecked()) {
                            if (!FavouriteCategoriesJsonParser.selectedCategories.contains(String.valueOf(list.get(getPosition).getCateogry_id()))) {
                                FavouriteCategoriesJsonParser.selectedCategories.add(String.valueOf(list.get(getPosition).getCateogry_id()));
                                Log.i("ISIS_back"," "+"ADICONOU "+String.valueOf(list.get(getPosition).getCateogry_id()));
                            }
                        } else {
                            if (FavouriteCategoriesJsonParser.selectedCategories.contains(String.valueOf(list.get(getPosition).getCateogry_id()))) {
                                FavouriteCategoriesJsonParser.selectedCategories.remove(String.valueOf(list.get(getPosition).getCateogry_id()));
                                Log.i("ISIS_back"," "+"REMOVEU "+String.valueOf(list.get(getPosition).getCateogry_id()));
                            }
                        }
                    }
                });
                convertView.setTag(viewHolder);
                convertView.setTag(R.id.row_categoryname_textview, viewHolder.categoryName);
                convertView.setTag(R.id.row_category_checkbox, viewHolder.categoryCheckBox);
            } else {
                viewHolder = (ViewHolder) convertView.getTag();
            }
            viewHolder.categoryCheckBox.setTag(position);
            viewHolder.categoryName.setText(list.get(position).getCategory_Name());
            viewHolder.categoryCheckBox.setChecked(list.get(position).isSelected());

            return convertView;
        }
    }

    public static class FavouriteCategoriesJsonParser {
        public static ArrayList<String> selectedCategories = new ArrayList<>();

        public ArrayList<Category> getParsedCategories() {
            String JsonFavouriteCategories = "";
            ArrayList<Category> MyArraylist = new ArrayList<>();
            HttpClient httpClient = new DefaultHttpClient();
            HttpGet httpGet = new HttpGet("https://pensoupediu.000webhostapp.com/api/filtro/getFavouriteCategories.php?id_usuario=1");
            try {
                HttpResponse httpResponse = httpClient.execute(httpGet);
                JsonFavouriteCategories = EntityUtils.toString(httpResponse.getEntity());
                JSONArray jsonArray = new JSONArray(JsonFavouriteCategories);

                for (int i = 0; i < jsonArray.length(); i++) {
                    Category genres = new Category();
                    JSONObject MyJsonObject = jsonArray.getJSONObject(i);
                    genres.setCateogry_id(Integer.parseInt(MyJsonObject.getString("id")));
                    genres.setCategory_Name(MyJsonObject.getString("nome_cat"));
                    genres.setSelected(Boolean.parseBoolean(MyJsonObject.getString("selected")));
                    MyArraylist.add(genres);
                    if (MyJsonObject.getString("selected").equals("true")) {
                        selectedCategories.add(MyJsonObject.getString("id"));
                    }
                }

            } catch (Exception e) {
                e.printStackTrace();
            }
            return MyArraylist;
        }
    }

    public class asyncTask_getCategories extends AsyncTask<Void, Void, Void> {
        ProgressDialog dialog = new ProgressDialog(context);

        @Override
        protected void onPreExecute() {
            dialog.setTitle("");
            dialog.setMessage("Carregando...");
            dialog.show();
            array_list = new ArrayList<>();
            categoryJsonParser = new FavouriteCategoriesJsonParser();
            super.onPreExecute();
        }

        @Override
        protected Void doInBackground(Void... params) {
            array_list = categoryJsonParser.getParsedCategories();

            Log.i("ISIS"," "+array_list);

            return null;
        }

        @Override
        protected void onPostExecute(Void s) {



            ListView mListViewBooks = (ListView) findViewById(R.id.category_listView);
            final CategoryAdapter categoryAdapter = new CategoryAdapter(context, R.layout.row_category, array_list);
            mListViewBooks.setAdapter(categoryAdapter);
            Button button = (Button) findViewById(R.id.selectCategoryButton);
            button.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    categoriesCsv = FavouriteCategoriesJsonParser.selectedCategories.toString();
                    categoriesCsv = categoriesCsv.substring(1, categoriesCsv.length() - 1);

                    if (categoriesCsv.length() > 0) {
                        new asyncTask_insertUpdatefavouriteCategories().execute();

                    } else {
                        Toast.makeText(context, "Por favor, selecione um filtro.", Toast.LENGTH_SHORT).show();
                    }
                }
            });
            super.onPostExecute(s);
            dialog.dismiss();
        }

        public class asyncTask_insertUpdatefavouriteCategories extends AsyncTask<Void, Void, Void> {

            String response;

            @Override
            protected Void doInBackground(Void... params) {
                response = insertUpdateCall(categoriesCsv);

                return null;

            }

            @Override
            protected void onPostExecute(Void s) {

                Toast.makeText(context, categoriesCsv, Toast.LENGTH_LONG).show();

                Intent intent = new Intent(context, NovaActivity.class);
                intent.putExtra("filtros", response);

                startActivity(intent);

                super.onPostExecute(s);

            }
        }
    }

    public static String insertUpdateCall(String categoriesCsv) {
        String response = "";
        HttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost("https://pensoupediu.000webhostapp.com/api/filtro/insertUpdateFavouriteCategories.php");
        try {
            ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
            nameValuePairs.add(new BasicNameValuePair("id_usuario", "1"));
            nameValuePairs.add(new BasicNameValuePair("favouriteCategories", categoriesCsv));
            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse httpResponse = httpClient.execute(httpPost);
            response = EntityUtils.toString(httpResponse.getEntity());


        } catch (Exception e) {
            e.printStackTrace();
        }

        return response;

    }

}

【问题讨论】:

    标签: android listview checkbox


    【解决方案1】:

    使用 Set 代替 ArrayList:

    public static Set<String> selectedCategories = new HashSet<>();
    

    这将确保您的 selectedCategories 没有重复。

    【讨论】:

    • 非常感谢您拯救了我的一天,它运行良好。
    • 很高兴能为您提供帮助!
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