将数据从片段列表视图项传递到活动字符串变量 onitemclicklistener

Posted 2023-04-19

【中文标题】将数据从片段列表视图项传递到活动字符串变量 onitemclicklistener

【英文标题】：Passing Data from Fragment listview item to Activity string variable onitemclicklistener

【发布时间】：2018-04-14 22:10:12

【问题描述】：

我正在尝试将 ListView 项从片段传递到活动中的字符串变量“url”，意图成功创建活动，但是当我尝试传递数据时遇到问题。 片段类有一个带有 json 数据的列表视图，它显示图片、标题和 名称 的列表。当用户选择一个项目时，它会将他们带到活动中。我希望他们的选择将 name 从列表视图转移到其他活动中的 url 变量。因此片段中的网址从“https://.....id=”更改为“https://.....id=”+name。 这将使 recyclerview 更改为单击任何列表视图项的新 url。

我的片段：

public class Accueil extends Fragment 

ArrayList<articles> arrayList;
ListView lv;
public static String URL1=null;
class ReadJSON extends AsyncTask<String, Integer, String> 

    @Override
    protected String doInBackground(String... params) 
        return readURL(params[0]);
    

    @Override
    protected void onPostExecute(String content) 
        JSONObject jsonObject = null;
        try 
            jsonObject = new JSONObject(content);
         catch (JSONException e1) 
            e1.printStackTrace();
        
        JSONArray jsonArray = null;
        try 
            jsonArray = jsonObject.getJSONArray("articles");
         catch (JSONException e1) 
            e1.printStackTrace();
        
        for (int i = 0; i < jsonArray.length(); i++) 
            JSONObject articlesobject = null;
            try 
                articlesobject = jsonArray.getJSONObject(i);
             catch (JSONException e1) 
                e1.printStackTrace();
            
            try 
                arrayList.add(new articles(
                        articlesobject.getString("picture"),
                        articlesobject.getString("title"),
                        articlesobject.getString("name")
                ));
             catch (JSONException e1) 
                e1.printStackTrace();
            
            CustomListAdaper adaper = new CustomListAdaper(
                    getActivity().getApplicationContext(), 
R.layout.custom_list_layout, arrayList
            );
            lv.setAdapter(adaper);
        

    


    private String readURL(String theURL) 
        StringBuilder content = new StringBuilder();
        try 
            URL url = new URL(theURL);
            URLConnection urlConnection = url.openConnection();
            BufferedReader bufferedReader = new BufferedReader(new 
InputStreamReader(urlConnection.getInputStream()));
            String line;
            while ((line = bufferedReader.readLine()) != null) 
                content.append(line + "\n");
            
            bufferedReader.close();
         catch (Exception e) 
            e.printStackTrace();
        
        return content.toString();
    

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                     Bundle savedInstanceState) 
arrayList = new ArrayList<>();
View rootView = inflater.inflate(R.layout.accueil, container, false);
lv = (ListView) rootView.findViewById(R.id.ListView1);
getActivity().runOnUiThread(new Runnable() 
    @Override
    public void run() 
        new Accueil.ReadJSON().execute("http://wach.ma/mobile/home.php");
    

);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() 
    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int 
position, long id) 

        String selectedFromList = 
(lv.getItemAtPosition(position).toString());

        Intent i = new Intent(getActivity(), Test.class);

        i.putExtra("name", selectedFromList);
         startActivity(i);
    

);
return rootView;

我的活动：

public class Test extends AppCompatActivity 
public String URL_DATA="http://wach.ma/mobile/category.php?id=";

private RecyclerView recyclerView;
private RecyclerView.Adapter adapter;
private List<ListItem> listItems;

protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_test);
    recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    listItems = new ArrayList<>();
    Intent i = getIntent();
    String s1 = i.getStringExtra("name");
    URL_DATA=URL_DATA+s1;
    loadRecyclerViewData();

private void loadRecyclerViewData()
    final ProgressDialog progressDialog = new ProgressDialog(this);
    progressDialog.setMessage("Chargement...");
    progressDialog.show();
    StringRequest stringRequest = new StringRequest(Request.Method.GET, 
URL_DATA, new Response.Listener<String>() 
        @Override
        public void onResponse(String s) 
            progressDialog.dismiss();
            try 
                JSONObject jsonObject = new JSONObject(s);
                JSONArray array = jsonObject.getJSONArray("articles");

                for(int i = 0; i<array.length();i++)
                    JSONObject o = array.getJSONObject(i);
                    ListItem item = new ListItem(
                            o.getString("picture"),
                            o.getString("name"),
                            o.getString("city"),
                            o.getString("add_time"),
                            o.getString("price")
                    );
                    listItems.add(item);
                
                adapter = new Myadapter(listItems, getApplicationContext());
                recyclerView.setAdapter(adapter);
             catch (JSONException e) 
                e.printStackTrace();
            

        
    ,
            new Response.ErrorListener() 
                @Override
                public void onErrorResponse(VolleyError volleyError) 
                    Toast.makeText(getApplicationContext(), 
volleyError.getMessage(), Toast.LENGTH_LONG).show();

                
            );
    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(stringRequest);

提前谢谢你，我很抱歉我的英语不好

【参考方案1】：

我认为您的问题来自于此：String selectedFromList = (lv.getItemAtPosition(position).toString());

lv.getItemAtPosition(position) 返回一个 Object，它是 listView Adapter 的一个项目！ 在这个对象上调用toString() 不会返回任何好处:)

OnClickListener 有一个 View in 参数，它是父视图，在您的情况下，是您单击的项目视图。 您可以检索保存在 OnClickListener 中的名称字段的 TextView 并获取此 TextView 的字符串，如下所示：

@Override
public void onItemClick(AdapterView<?> parent, View view, int postion, long id) 
    String name = ((TextView) view.findViewById(R.id.myNameField)).getText().toString();

希望对你有帮助:)

PS : 下次也发布你的 XML 代码 ;)

【参考方案2】：

我修好了，改一下：

lv.setOnItemClickListener(new AdapterView.OnItemClickListener() 
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int 
position, long id) 

    String selectedFromList = 
(lv.getItemAtPosition(position).toString());

    Intent i = new Intent(getActivity(), Test.class);

    i.putExtra("name", selectedFromList);
     startActivity(i);


);
return rootView;

到这里：

lv.setOnItemClickListener(new AdapterView.OnItemClickListener() 
    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int 
position, long id) 

        String selectedFromList= 
String.valueOf(arrayList.get(position).getIdd());

        Intent i = new Intent(getActivity(), Test.class);

        i.putExtra("name", selectedFromList);
         startActivity(i);
    

);
return rootView;