MP Android Diagramm keine Daten avi

Question

Ich habe ein Diagramm erstellt, das mehrere Datensätze aus meiner Datenbank bekommen wird, aber es zeigt nicht in der Grafik und zeigt nur keine Daten zur Verfügung. Kann jemand auf das Problem hinweisen? Ich habe versucht, die mpandroidchart Anleitung zu lesen, aber ich kann immer noch nicht auf das Problem hinweisen. Danke im Voraus

public ArrayList<String> queryXData(){ 
    ArrayList<String> xNewData = new ArrayList<String>(); 
    String query = "SELECT Subject FROM gradesinfo ORDER BY Subject"; 
    Cursor cursor = cn.rawQuery(query, null); 
    for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) { 
     xNewData.add(cursor.getString(cursor.getColumnIndex("Subject"))); 
    } 
    cursor.close(); 
    return xNewData; 
} 

public ArrayList<Float> queryYData(){ 
    ArrayList<Float> yNewData = new ArrayList<Float>(); 
    String query = "SELECT PG FROM gradesinfo ORDER BY Subject"; 
    Cursor cursor = cn.rawQuery(query, null); 
    for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) { 
     yNewData.add(cursor.getFloat(cursor.getColumnIndex("PG"))); 
    } 
    cursor.close(); 
    return yNewData; 
} 


public ArrayList<Float> queryYData2(){ 
    ArrayList<Float> yNewData2 = new ArrayList<Float>(); 
    String query = "SELECT MG FROM gradesinfo ORDER BY Subject"; 
    Cursor cursor = cn.rawQuery(query, null); 
    for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) { 
     yNewData2.add(cursor.getFloat(cursor.getColumnIndex("MG"))); 
    } 
    cursor.close(); 
    return yNewData2; 
} 


public ArrayList<Float> queryYData3(){ 
    ArrayList<Float> yNewData3 = new ArrayList<Float>(); 
    String query = "SELECT FG FROM gradesinfo ORDER BY Subject"; 
    Cursor cursor = cn.rawQuery(query, null); 
    for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) { 
     yNewData3.add(cursor.getFloat(cursor.getColumnIndex("FG"))); 
    } 
    cursor.close(); 
    return yNewData3; 
} 


private void addData(){ 
    Cursor cursor = cn.rawQuery("SELECT PG, MG, FG FROM gradesinfo ORDER BY Subject", null); 

    if(cursor.getCount()>=2){ 

     ArrayList<BarEntry> yVals = new ArrayList<BarEntry>(); 
     for (int i = 0; i < queryYData().size(); i++) 
      yVals.add(new BarEntry(queryYData().get(i), i)); 

     ArrayList<BarEntry> yVals1 = new ArrayList<BarEntry>(); 
     for (int i = 0; i < queryYData2().size(); i++) 
      yVals1.add(new BarEntry(queryYData2().get(i), i)); 

     ArrayList<BarEntry> yVals2 = new ArrayList<BarEntry>(); 
     for (int i = 0; i < queryYData3().size(); i++) 
      yVals2.add(new BarEntry(queryYData3().get(i), i)); 

     ArrayList<String> xVals = new ArrayList<String>(); 
     for(int i = 0; i < queryXData().size(); i++) 
      xVals.add(queryXData().get(i)); 

     BarDataSet dataSet = new BarDataSet(yVals, "Prelim"); 
     dataSet.setColors(ColorTemplate.COLORFUL_COLORS); 

     BarDataSet dataSet2 = new BarDataSet(yVals1, "Midterm"); 
     dataSet2.setColors(ColorTemplate.COLORFUL_COLORS); 

     BarDataSet dataSet3 = new BarDataSet(yVals2, "Finals"); 
     dataSet3.setColors(ColorTemplate.COLORFUL_COLORS); 


     ArrayList<BarDataSet> dataset = new ArrayList<BarDataSet>(); 
     dataset.add(dataSet); 
     dataset.add(dataSet2); 
     dataset.add(dataSet3); 

     BarData data = new BarData(xVals, dataset); 


     LimitLine line = new LimitLine(75f, "Passing Grade"); 
     line.setTextSize(8f); 
     line.setLineWidth(4f); 
     YAxis leftAxis = barChart.getAxisLeft(); 
     leftAxis.addLimitLine(line); 

     barChart.setData(data); 
     barChart.setDescription("Grades Chart"); 
     barChart.animateY(2000); 
    } 

Answer 1

Ich vermute, dass Ihr Diagramm nicht über empfangene Daten weiß. Tell-Tabelle zu tun: