如何在绿道android中只显示7天的记录

Question

我正在插入所有数据并在图中显示，但如何只显示greendao的最后7天图？

例如：

1. 如果我今天开始插入数据。它应该只显示今天的日期。（例如：2007年22日）
2. 然后第二天，它将插入数据。（然后我需要显示22/07、23/07）
3. 如果我的当前日期是2007年7月30日，那么我需要显示（07年7月23日、07年07月24日至07年30日），忽略其他数据，即07年22日

但我正在获取所有数据并在我的案例中显示。即从2007年22月到2007年30月。如何通过删除旧的7天来显示。请帮我解决这个问题。

这是我的代码，它显示所有数据。

在DetectiveGraphExcector:中

public List<DetectiveGraph> getDetectionsGraphBetweenTime(Date    fromDateAndTime, Date toTimeAndDate) {
    List<DetectiveGraph>  mTask = mDetectiveGraphDao.queryBuilder().where(DetectiveGraphDao.Properties.Detective_date.between(fromDateAndTime, toTimeAndDate)).list();
    closeSession();
    return mTask;
}
  public List<DetectiveGraph> getAllDetections() { //getting all datas
    return mDetectiveGraphDao.queryBuilder().orderAsc(DetectiveGraphDao.Properties.Detective_date).list();
}
 public class ActivityTracking extends Activity{
 private DetectiveGraphExecutor mDetectiveGraphExecutor;
 private List<DetectiveGraph> mDetectiveGraphList;
 private int columnIndex;
 private List<DetectiveGraph> activities; //The activities.
@Override
 protected void onCreate(Bundle savedInstanceState) { //onCreate
    super.onCreate(savedInstanceState); //super
 setContentView(R.layout.activity_tracking);
 mDetectiveGraphList = mDetectiveGraphExecutor.getAllDetections(); 
 maxDate =  mDetectiveGraphList.get(mDetectiveGraphList.size()-1).getDetectiveDate();
 toDates = maxDate; // maximumDate
 Calendar toDateCalendar = Calendar.getInstance(); //toDateCalendar
   toDateCalendar.setTime(toDates); //toDateCalendar
 Calendar fromDateCalendar = (Calendar) toDateCalendar.clone();  
 fromDateCalendar.add(Calendar.DATE, -7); //fromDateCalendar
 fromDateCalendar.add(Calendar.MINUTE, -fromDateCalendar.get(Calendar.MINUTE)); //minute
                fromDateCalendar.set(Calendar.SECOND, 0); //second
                Long initialLogTime = Long.valueOf(VALRTApplication.getPrefString(ActivityTracking.this, "epochTime"));
                Calendar calendar = Calendar.getInstance(); //calendar
                calendar.setTimeInMillis(initialLogTime); //setTime
                calendar.add(Calendar.MINUTE, -calendar.get(Calendar.MINUTE)); //minute
                calendar.set(Calendar.SECOND, 0); //second
                Calendar fromDateTime = calendar; //fromDate
                columnIndex = -1; //columnIndex
                do {
                    Date fromDate = null, toDate = null; //fromDate
                    Calendar toDateTime = (Calendar) fromDateTime.clone(); //toDate
                    toDateTime.add(Calendar.MINUTE, 60); //toDateTime
                    SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy hh:mm:ss:aa"); //dateFormat
                    dateString = dateFormat.format(fromDateTime.getTime()); //dateString
                    dateString1 = dateFormat.format(toDateTime.getTime()); //dateString1
                    try {
                        fromDate = dateFormat.parse(dateString); //dateString
                        toDate = dateFormat.parse(dateString1);//toDate
                    } catch (ParseException e) {
                        LogUtils.e(VALRTApplication.TAG, e); //exceptional handling
                    }
                    if (fromDate != null && toDate != null) { //fromDate and to date not null
                        updateGraph(fromDate, toDate, entries, labels);
                    }
                    textName.setText(iAddedDate); //setText
                    fromDateTime.add(Calendar.HOUR, 1); //add
                }
                while (Calendar.getInstance().getTimeInMillis() >= fromDateTime.getTimeInMillis()); //getTime
              }
    //in this I am updating graph based on the date and updating in UI. 
private void updateGraph(Date fromDate, Date toDate, List<BarEntry> entries, ArrayList<String> labels) {
    activities = mDetectiveGraphExecutor.getDetectionsGraphBetweenTime(fromDate, toDate); //getDetectionGraph
    SimpleDateFormat dateFormats = new SimpleDateFormat("h:aa"); //hour and am/pm
    SimpleDateFormat withDateTimes = new SimpleDateFormat("MM/dd/yyyy"); //withDateTimes
    iAddedDate = withDateTimes.format(toDate.getTime()); //getTime
    String newDate = iAddedDate.substring(0, iAddedDate.length() - 5); //newDate
    String dateToTimes = dateFormats.format(toDate.getTime()); //getTime
    String replaceTime = dateToTimes.replaceAll(":", " ").toUpperCase(); //toUpperCase
    String outputDates = "n" + newDate + "n" + replaceTime; //replaceTime
    entries.add(new BarEntry(activities.size(), ++columnIndex)); //columnIndex
    labels.add(outputDates); //outputDates
    BarDataSet dataset = new BarDataSet(entries, ""); //dataset
    BarData data = new BarData(labels, dataset); //data
    data.setDrawValues(false); //setDrawValues
    barChart.setData(data); //setData
}

Answer 1

如果我正确理解您的问题，我认为从数据库中只获取所需的数据会更容易。为了做到这一点，您应该使用类似的方法，假设Detective_date是一个日期类型的列。

Calendar toDateCalendar = Calendar.getInstance();
Calendar fromDateCalendar = Calendar.getInstance()  
fromDateCalendar.add(Calendar.DATE, -7);
List<DetectiveGraph> filteredDetections = mDetectiveGraphDao.queryBuilder()
 .where(DetectiveGraphDao.Properties.Detective_date.ge(fromDateCalendar.getTime()),
        DetectiveGraphDao.Properties.Detective_date.le(toDateCalendar.getTime()))
 .orderAsc(DetectiveGraphDao.Properties.Detective_date)
 .list();