无法刷新Spinner所选项的ListView以从url获取新数据

Question

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我无法刷新旋转项选择上的列表视图。

我希望基于spinner的items值构建新的url，以获取新的json数据并转换为ListView。

您还可以帮助我说明如何创建一个方法来传递新url以获取新数据。

主要问题与标题相同，您的每一个帮助都将不胜感激。

String [] array_values = {"All "," 5"," 4"," 3"," 2"," 1"};
final Spinner spinner = view.findViewById(R.id.spinner);

final ArrayAdapter<String> spinner_adapter = new ArrayAdapter<>(this.getActivity(), android.R.layout.simple_spinner_item, array_values);
spinner_adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
spinner.setAdapter(spinner_adapter);

final String spinnerValue = spinner.getSelectedItem().toString();
url = "http://website.com/demo.php?pswd=kvpswd";

listView = (ListView) view.findViewById(R.id.demo_list_view);
adapter = new CustomListAdapter(this.getActivity(), List);
listView.setAdapter(adapter);

spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
      //  listView.setAdapter(null);
      String spinnerValue = spinner.getSelectedItem().toString();
        url = "http://website.com/demo.php?pswd="+spinnerValue;
        adapter.notifyDataSetChanged();
    }
    public void onNothingSelected(AdapterView<?> parent) {

    }
});

// Creating volley request obj
JsonArrayRequest Requset = new JsonArrayRequest(url,
        new Response.Listener<JSONArray>() {
            @Override
            public void onResponse(JSONArray response) {
                Log.d(TAG, response.toString());
                hidePDialog();

                // Parsing json
                for (int i = 0; i < response.length(); i++) {
                    try {

                        JSONObject obj = response.getJSONObject(i);

                        DataFetcher datafetcher = new DataFetcher();

                        datafetcher.set1(obj.getString("item1"));
                        datafetcher.set2(obj.getString("item2"));
                        datafetcher.set3(obj.getString("item3"));
                        datafetcher.set4(obj.getString("item4"));
                        datafetcher.set5(obj.getString("item5"));
                        datafetcher.set6(obj.getString("item6"));
                        datafetcher.set7(obj.getString("item7"));
                        datafetcher.set8(obj.getString("item8"));

                        // adding list to list array
                        List.add(datafetcher);

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

                }

                // notifying list adapter about data changes
                // so that it renders the list view with updated data
                adapter.notifyDataSetChanged();
            }
        }, new Response.ErrorListener() {
    @Override
    public void onErrorResponse(VolleyError error) {
        VolleyLog.d(TAG, "Error: " + error.getMessage());
        hidePDialog();

    }
});

Answer 1

方法用于api调用，并将url和设置数据传递到列表视图中。下面的方法进入旋转器选择时间。

 private void callApiData(String url){
    // Creating volley request obj
    JsonArrayRequest Requset = new JsonArrayRequest(url,
            new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    Log.d(TAG, response.toString());
                    hidePDialog();

                    // Parsing json
                    for (int i = 0; i < response.length(); i++) {
                        try {

                            JSONObject obj = response.getJSONObject(i);

                            DataFetcher datafetcher = new DataFetcher();

                            datafetcher.set1(obj.getString("item1"));
                            datafetcher.set2(obj.getString("item2"));
                            datafetcher.set3(obj.getString("item3"));
                            datafetcher.set4(obj.getString("item4"));
                            datafetcher.set5(obj.getString("item5"));
                            datafetcher.set6(obj.getString("item6"));
                            datafetcher.set7(obj.getString("item7"));
                            datafetcher.set8(obj.getString("item8"));

                            // adding list to list array
                            List.add(datafetcher);
                            setAdapter();
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                    }

                    // notifying list adapter about data changes
                    // so that it renders the list view with updated data
                    adapter.notifyDataSetChanged();
                }
            }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d(TAG, "Error: " + error.getMessage());
            hidePDialog();

        }
    });
}

并为适配器设置制定了一个单独的方法。

  private void setAdapter(){
    if(adpter==null){
        adapter = new CustomListAdapter(this.getActivity(), List);
        listView.setAdapter(adapter);
        adapter.notifyDataSetChanged();
    }
    else{
        adapter.notifyDataSetChanged();
    }
}