我已经写了这段代码。不知何故，当我在我的适配器上调用notifyDatasetChanged时，它不起作用。任何人都可以解释为什么这不起作用。
我还有另一个问题（我认为与此相关）我在创建课程HoodID = 27时给出了但我怎么能以另一种方式做到这一点因为当我这样做时我无法选择我的微调器中的第一项。
package com.example.sander.app;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.Context;
import android.location.Location;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.Spinner;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.jjoe64.graphview.GraphView;
import com.jjoe64.graphview.LegendRenderer;
import com.jjoe64.graphview.helper.StaticLabelsFormatter;
import com.jjoe64.graphview.series.BarGraphSeries;
import com.jjoe64.graphview.series.DataPoint;
import com.jjoe64.graphview.series.DataPointInterface;
import com.jjoe64.graphview.series.LineGraphSeries;
import com.jjoe64.graphview.series.OnDataPointTapListener;
import com.jjoe64.graphview.series.Series;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import android.R.layout.*;
import android.widget.Toast;
/**
* Created by Sander on 8-4-2017.
*/
public class GraphFrame extends Fragment implements AdapterView.OnItemSelectedListener {
Integer hoodSelector = 27;
ArrayList<HoodData> hoodDataList = new ArrayList<>();
ArrayList<String> hoodList = new ArrayList<>();
Context mContext;
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
public void refreshFragment(){
hoodDataList.clear();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.detach(this).attach(this).commit();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_graph,
container, false);
//API Request for all the hoods
getDataFromApi((GraphView) view.findViewById(R.id.graph));
getDataForSpinner((Spinner) view.findViewById(R.id.spinner));
return view;
}
public void setHoodId(Integer hood){
hoodSelector = hood;
}
public void getDataFromApi(final GraphView graph) {
RequestQueue rq = Volley.newRequestQueue(getActivity().getApplicationContext());
String url= "http://test.dontstealmywag.ga/api/damage_or_theft_car_wijk.php?hood_id=" + hoodSelector;
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
// Do something with the response
try{
JSONObject o = new JSONObject(response);
JSONArray values=o.getJSONArray("");
for (int i = 0; i < values.length(); i++) {
JSONObject jsonObject = values.getJSONObject(i);
hoodDataList.add(new HoodData(jsonObject.getDouble("percentage"), jsonObject.getInt("hood_id"), jsonObject.getInt("year"), jsonObject.getString("hood_name")));
}
} catch (JSONException ex){}
StaticLabelsFormatter staticLabelsFormatter = new StaticLabelsFormatter(graph);
LineGraphSeries<DataPoint> series = new LineGraphSeries<>(new DataPoint[] {
new DataPoint(1, hoodDataList.get(0).getPercentage()),
new DataPoint(2, hoodDataList.get(1).getPercentage()),
new DataPoint(3, hoodDataList.get(2).getPercentage()),
new DataPoint(4, hoodDataList.get(3).getPercentage()),
new DataPoint(5, hoodDataList.get(4).getPercentage())
//new DataPoint(12, 0)
});
// set manual x bounds
staticLabelsFormatter.setHorizontalLabels(new String[] {"2006", "2007","2008","2009","2011"});
//creates custom x-axis
graph.getGridLabelRenderer().setLabelFormatter(staticLabelsFormatter);
graph.setTitle("Wijk " + hoodSelector + " - " + hoodDataList.get(0).getHood_name());
//set nice background color :)
series.setDrawBackground(true);
//shows points at datapoints
series.setDrawDataPoints(true);
//size of the points
series.setDataPointsRadius(10.0f);
series.setOnDataPointTapListener(new OnDataPointTapListener() {
@Override
public void onTap(Series series, DataPointInterface dataPoint) {
Toast.makeText(getActivity(), "Punt "+ dataPoint, Toast.LENGTH_SHORT).show();
}
});
series.setTitle("%");
series.setAnimated(true);
graph.getLegendRenderer().setVisible(true);
graph.getLegendRenderer().setAlign(LegendRenderer.LegendAlign.TOP);
graph.addSeries(series);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// Handle error
}
});
rq.add(stringRequest);
}
public void getDataForSpinner(final Spinner spinner){
RequestQueue rq = Volley.newRequestQueue(getActivity().getApplicationContext());
String url= "http://test.dontstealmywag.ga/api/damage_or_theft_car_wijk.php";
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
// Do something with the response
try{
JSONObject o = new JSONObject(response);
JSONArray values=o.getJSONArray("");
for (int i = 0; i < values.length(); i++) {
JSONObject jsonObject = values.getJSONObject(i);
if (!hoodList.contains(jsonObject.getString("hood_name"))) {
hoodList.add(jsonObject.getString("hood_name"));
}
}
} catch (JSONException ex){}
final ArrayAdapter<String> adapter = new ArrayAdapter<String>(spinner.getContext(), android.R.layout.simple_spinner_item, hoodList);
// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
spinner.setPrompt("Title");
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String item = parent.getItemAtPosition(position).toString();
// Showing selected spinner item
for(int i = 1; i < hoodList.size(); i++) {
if (item.equals(hoodList.get(i))) {
setHoodId(i + 27);
adapter.notifyDataSetChanged();
}
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// Handle error
}
});
rq.add(stringRequest);
}
}
答案 0 :(得分：0)
声明
private GraphView mGraphView;
private Spinner mSpinner;
private ArrayAdapter<String> adapter;
删除方法getDataFromApi和getDataForSpinner中的参数。
召回getDataFromApi而不是adapter.notifyDataSetChanged();
在adapter.notifyDataSetChanged();
onResponse末尾添加getDataFromApi