这是我第一次使用Graph并且它无法正常工作。我可以绘制静态折线图，但我无法使用动态数据绘制折线图。图表如何绘制动态数据？
fragment_dashboard
<com.github.mikephil.charting.charts.LineChart
android:id="@+id/chart1"
android:layout_width="match_parent"
android:layout_height="match_parent" />
控制台
public class Dashboard extends Fragment {
ListView listViewNotice, listviewpendingbills;
String Navigation_URL = "http://192.168.100.5:84/api/academics/getNotices";
String Navigation_URL_BIlls = "http://192.168.100.5:84/Api/financeApi/getAllFees";
String Navigation_URL_CHART = "http://192.168.100.5:84/api/academics/getSingleStudentsMarks";
String access_token;
String Notice, BillNumber, Status, AmountPaid, ReceiptIssueDate;
String master_id;
TextView pendingbills, NoNotice;
BarChart lineChart;
LineChart chart;
private static final String TAG = "Test";
ArrayList<Entry> entries = new ArrayList<>();
LineDataSet set = new LineDataSet(entries, "Wow");
LineData data = new LineData(set);
ArrayList<Object> labels = new ArrayList<>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_dashboard, container, false);
// getActivity().setTitle("St. Xavier's High School");
setHasOptionsMenu(true);
listViewNotice = (ListView) view.findViewById(R.id.list_student_notice_dashboard);
listviewpendingbills = (ListView) view.findViewById(R.id.student_dashboard_pendingbills);
pendingbills = (TextView) view.findViewById(R.id.textpendingbills);
NoNotice = (TextView) view.findViewById(R.id.textnoticedashboard);
// lineChart = (BarChart) view.findViewById(R.id.chart1);
chart = (LineChart) view.findViewById(R.id.chart1);
SessionManagement session = new SessionManagement(getContext());
session.checkLogin();
access_token = session.getAccesstToken();
master_id = session.getMasterId();
makeJsonObjectRequest();
makeJsonObjectRequestBills();
makeJsonObjectRequestGraph();
return view;
}
private void makeJsonObjectRequestGraph() {
RequestQueue requestQueue = Volley.newRequestQueue(getContext());
String URL1 = Navigation_URL_CHART + "?StdID=" + master_id;
StringRequest stringRequest = new StringRequest(Request.Method.GET, URL1,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
JSONArray jArray = new JSONArray(response);
for (int i = 0; i < jArray.length(); i++) {
JSONObject jsonObject = jArray.getJSONObject(i);
String Marks = jsonObject.getString("Marks");
String examDescription = jsonObject.getString("examDescription");
if (examDescription == "First Term") {
entries.add(new BarEntry(Float.parseFloat(Marks), i));
}
}
chart.notifyDataSetChanged();
chart.invalidate();
set = new LineDataSet(entries, "Wow");
//data = new LineData(labels,set);
chart.setData(data);
setListViewHeightBasedOnChildren(listviewpendingbills);
} catch (JSONException e) {
Toast.makeText(getContext(), "Fetch failed!", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getContext(), error.toString(), LENGTH_LONG).show();
}
}) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String, String> headers = new HashMap<String, String>();
headers.put("Authorization", "Bearer " + access_token);
headers.put("Content-Type", "application/x-www-form-urlencoded");
return headers;
}
/*
@Override
protected Map<String, String> getParams() throws com.android.volley.AuthFailureError {
Map<String, String> map = new HashMap<String, String>();
map.put("id", master_id);
map.put("accessID", accessID);
map.put("currentUser", master_id);
return map;
} */
};
requestQueue.add(stringRequest);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// TODO Auto-generated method stub
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.dashboard, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// handle item selection
switch (item.getItemId()) {
case R.id.action_settings:
// do s.th.
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public static void setListViewHeightBasedOnChildren(ListView listView) {
ListAdapter listAdapter = listView.getAdapter();
if (listAdapter == null) {
// pre-condition
return;
}
int totalHeight = 0;
int desiredWidth = View.MeasureSpec.makeMeasureSpec(listView.getWidth(), View.MeasureSpec.AT_MOST);
for (int i = 0; i < listAdapter.getCount(); i++) {
View listItem = listAdapter.getView(i, null, listView);
listItem.measure(desiredWidth, View.MeasureSpec.UNSPECIFIED);
totalHeight += listItem.getMeasuredHeight();
}
ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
listView.setLayoutParams(params);
listView.requestLayout();
}
}
JSON
[
{
"CLASSNO": "8",
"CLASS_ID": 8,
"CourseID": 1012,
"Marks": 80,
"Sno": 1,
"StdID": 2,
"TermID": 6014,
"CourseName": "Math",
"Terminal_FM": 100,
"Terminal_PM": 40,
"UT_FM": 50,
"UT_PM": 20,
"examDescription": "First Term",
"type": "Terminal",
"NAME": "Oren Oneill"
},
{
"CLASSNO": "8",
"CLASS_ID": 8,
"CourseID": 1013,
"Marks": 80,
"Sno": 2,
"StdID": 2,
"TermID": 6014,
"CourseName": "Nepali",
"Terminal_FM": 100,
"Terminal_PM": 40,
"UT_FM": 50,
"UT_PM": 20,
"examDescription": "First Term",
"type": "Terminal",
"NAME": "Oren Oneill"
}
]
如何使用MPAndroidChart在Android中绘制动态数据？
答案 0 :(得分：0)
将ArrayList条目，LineDataSet，LineData作为全局，在onCreate中初始化它，然后在for循环中添加以下代码
if(examDescription.equals("First Term")){
entries.add(new BarEntry(Marks, i));}
在for循环后执行此操作，
chart.notifyDataSetChanged();
chart.invalidate();
set = new LineDataSet(entries, "Wow");
data = new LineData(labels,set);
chart.setData(data);