复选框列表视图 Mysql

Question

>我正在尝试使用复选框和列表视图使用过滤器解决此问题三天。

在此代码中，我第一次选中复选框，它们与每个选定类别的 ID 一起正确列出，并查看另一个名为 NovaActivity 的活动的 ID。还行？目前为止，一切都好。

当我重新打开过滤器活动以使用已经列出的过滤器制作一个新的相同的取消选中复选框时，问题如下，即使它们未标记，它也会继续进入 NovaAcitivty。

前任：  第一个过滤器选择 1 和 2;

当我把它发送给另一个人时，它会变成 1,2;

第二个过滤器我选择 1 并取消选中复选框 2;

当我把它发送给另一个人时，它会变成 1,1,2;

我该如何解决这个问题？

注意：第二次很重要，所以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，谢谢你的任何帮助。

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;
}
}

Answer 1

使用 Set 而不是 ArrayList：

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

这将确保您选择的类别没有重复项。