我正在尝试使用 AChartEngine 库在 sqlitedatabase 中显示包含数据的图表。我在数据库中有两条记录。有一条记录时显示的条形图。但是有两条数据记录，它说，“数据集和渲染器不应该为空，并且应该有相同数量的系列”。我不明白这一点。
我的代码是，
Button ReportGraph = (Button) findViewById(R.id.ReportGraph);
ReportGraph.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
GraphicalView GraphChartView = ChartFactory.getBarChartView(
getApplicationContext(), getWaterElectricityReading(),
getDemoRenderer(), Type.DEFAULT);
// Intent intent=ChartFactory.getLineChartIntent(this,
// getDemoDataset(), getDemoRenderer());
// startActivity(intent);
if (GraphChartView != null) {
GraphChartView.repaint();
}
relChartView.addView(GraphChartView);
mainLayout.setVisibility(View.GONE);
relChartView.setVisibility(View.VISIBLE);
}
});
private XYMultipleSeriesDataset getWaterElectricityReading() {
XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-mm-dd", Locale.US);
SimpleDateFormat df2 = new SimpleDateFormat("MMM dd yyyy");
Date StartDate;
Date EndDate;
String Pastdateformat = "";
String CurrentDateFormat = "";
SQLiteDatabase DB = Context
.openOrCreateDatabase("WaterElectricityReadingDataBase.db",
MODE_WORLD_READABLE, null);
Cursor c = DB
.rawQuery(
"select ReadingValue,strftime('%m/%d/%Y',StartDateTime) StartDateTime,strftime('%m/%d/%Y',EndDateTime) EndDateTime from WaterElectricity order by StartDateTime desc ",
null);
int rowCount = c.getCount();
if (c != null) {
if (rowCount > 0) {
if (c.moveToFirst()) {
do {
String ReadingValue = c.getString(c
.getColumnIndex("ReadingValue"));
String PastDate = c.getString(c
.getColumnIndex("StartDateTime"));
String CurrentDate = c.getString(c
.getColumnIndex("EndDateTime"));
try {
StartDate = df2.parse(PastDate);
Pastdateformat = sdf1.format(StartDate);
EndDate = df2.parse(CurrentDate);
CurrentDateFormat = sdf1.format(EndDate);
} catch (Exception e) {
}
XYSeries series = new XYSeries(
"WaterElectricityReading");
double ReadingVal = Double.parseDouble(ReadingValue);
series.add(rowCount, ReadingVal);
XYMultipleSeriesRenderer render = new XYMultipleSeriesRenderer();
dataset.addSeries(series);
rowCount++;
} while (c.moveToNext());
}
}
}
return dataset;
}
private XYMultipleSeriesRenderer getDemoRenderer() {
XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
renderer.setAxisTitleTextSize(12);
renderer.setChartTitleTextSize(12);
renderer.setLabelsTextSize(15);
renderer.setLegendTextSize(15);
renderer.setPointSize(5f);
renderer.setMargins(new int[] { 20, 30, 15, 0 });
XYSeriesRenderer r = new XYSeriesRenderer();
r.setColor(Color.GREEN);
r.setPointStyle(PointStyle.DIAMOND);
r.setFillBelowLine(false);
r.setFillPoints(true);
renderer.addSeriesRenderer(r);
setChartSettings(renderer);
return renderer;
}
private void setChartSettings(XYMultipleSeriesRenderer renderer) {
renderer.setChartTitle("Chart demo");
renderer.setXTitle("x values");
renderer.setYTitle("y values");
renderer.setApplyBackgroundColor(false);
renderer.setRange(new double[] { 0, 6, -70, 40 });
renderer.setFitLegend(false);
renderer.setAxesColor(Color.BLACK);
renderer.setShowGrid(true);
renderer.setXAxisMin(0);
renderer.setXAxisMax(10.5);
renderer.setYAxisMin(0);
renderer.setZoomEnabled(false);
renderer.setYAxisMax(1000);
}
对于两条记录，我希望显示两个条形图。任何人都可以指出错误。
任何帮助将不胜感激！！
谢谢。