MPAndroid Chart 在实时图表中设置 X

Question

I work for my school project on MPAndroidChart especially a realtime graph, i would like to display Time of the value.

I set a IndexAxisValueFormatter with a "getFormattedValue", it work but refresh every label and not just the last, I try to have for each entry in my graph a XLabel who show the time, I really don't know how to do that you're help would be welcome.

Code for create an entry and display it:

void creaGraph() {
    ArrayList<ILineDataSet> dataSets = new ArrayList<>();
    if (boxCO2.isChecked()) {
        A_CO2.add(new Entry(indice, listData.recup_data(indice - 1).getCO2()));
        LineDataSet setCO2 = new LineDataSet(A_CO2, "CO2");
        setCO2.setAxisDependency(YAxis.AxisDependency.LEFT);
        paramSet(setCO2);

        setCO2.setColor(Color.RED);
        setCO2.setCircleColor(Color.RED);
        dataSets.add(setCO2);
    }

    LineData data = new LineData(dataSets);
    graph.setData(data);
    data.notifyDataChanged();
    graph.notifyDataSetChanged();
    graph.invalidate();

}

The override of getFormattedValue

@Override
  public String getFormattedValue(float value) {
      return listData.recup_data(GraphPage.indice - 1).getTemps();

  }

And a picture of my issue Every label are refresh when a new entry come

Also, I see after the 7th values entry no longer have a time values

Answer 1

You never use value in getFormattedValue . The string you construct there should be based on value or it will show the same thing for every axis entry.

Something like this:

@Override
public String getFormattedValue(float value) {
   return makeDateStringAt(value);
}

For example, if you have a chart with axis values at 0, 1, 2, 3 then getFormattedValue will be called 4 times with 0f , 1f , 1f , and 3f as its arguments and you should use those inputs to create the appropriate string to show at those positions on the axis.