我有传感器值和日期时间格式的数据，其格式为(年-月-日期Thour:min:secZ)，例如“2019-05-29T12:48:18Z”值。我想打印所取的值来自传感器数据并在 x 轴中绘制图表作为日期时间，在 y 轴中绘制图表作为值。我知道如何绘制 yaxis 值以及如何添加 xaxis 标签也请帮助
这是我的 mobilefragment 类，它开始执行后台进程，以便从服务器获取数据并将其绘制在移动 fragment 类中(其中折线图位于 mobilefragmentactivity 中)
public class mobilefragment extends Fragment {
public static TextView data;
public static LineChart mchart;
public static Button click;
List<Entry> x;
ArrayList<String> y;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.mobile, container, false);
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mchart=view.findViewById(R.id.linechart);
click=view.findViewById(R.id.button);
click.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
fetchdata process=new fetchdata();
process.execute();
}
});
//data=view.findViewById(R.id.fetcheddata);
}
}
这是后台进程类，当 onpostexecution 之后从服务器获取数据时，数据将在 mobilefragment Activity 中绘制，并且我还希望 xaxis 中的日期时间格式存储在名为“y”的列表中
public class fetchdata extends AsyncTask<Void,Void,Void> {
String data="";
String dataparsed="";
String singleparsed="";
List<Entry> x;
List<String> y;
boolean flag=false;
/*Context ctx;
fetchdata(Context ctx) {
this.ctx = ctx;
}*/
@Override
protected Void doInBackground(Void... voids) {
x = new ArrayList<Entry>();
y = new ArrayList<String>();
try {
URL url=new URL("https://io.adafruit.com/api/v2/Yarev/feeds/pir-sensor/data");
HttpURLConnection httpURLConnection=(HttpURLConnection) url.openConnection();
InputStream inputStream=httpURLConnection.getInputStream();
BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream));
String line="";
while (line!=null)
{
line=bufferedReader.readLine();
data=data+line;
}
JSONArray JA=new JSONArray(data);
for(int i=0;i<JA.length();i++)
{
JSONObject JO= (JSONObject) JA.get(i);
singleparsed="Value:"+JO.get("value")+"\n"+
"Feed key:"+JO.get("feed_key")+"\n"+
"Created:"+JO.get("created_at")+"\n";
int value=JO.getInt("value");
float v1=value;
String time=JO.getString("created_at");
x.add(new Entry(i,v1));
y.add(time); //time string
dataparsed=dataparsed+singleparsed;
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
//mobilefragment.data.setText(this.dataparsed);
mobilefragment.mchart.setDragEnabled(true);
mobilefragment.mchart.setScaleEnabled(true);
mobilefragment.mchart.setDrawGridBackground(false);
mobilefragment.mchart.setTouchEnabled(true);
mobilefragment.mchart.setPinchZoom(false);
XAxis xl = mobilefragment.mchart.getXAxis();
xl.setAvoidFirstLastClipping(true);
YAxis leftAxis = mobilefragment.mchart.getAxisLeft();
leftAxis.setInverted(false);
YAxis rightAxis = mobilefragment.mchart.getAxisRight();
rightAxis.setEnabled(false);
Legend l = mobilefragment.mchart.getLegend();
l.setForm(Legend.LegendForm.LINE);
LineDataSet set1=new LineDataSet(x,"Data set 1");
set1.setFillAlpha(110);
set1.setValueTextColor(Color.GREEN);
List<ILineDataSet> datasets= new ArrayList<>();
datasets.add(set1);
LineData data=new LineData(datasets);
mobilefragment.mchart.setData(data);
mobilefragment.mchart.invalidate();
mobilefragment.click.setVisibility(View.INVISIBLE);
//activity.startActivity(new Intent(activity, Main2Activity.class));
}
public List<Entry> getList() {
return x;
}
}
最佳答案
https://github.com/jjoe64/GraphView
使用这个你可以达到你的要求
关于java - 如何在 x 轴作为日期时间和 y 轴作为值之间绘制图表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/56421999/