android viewpage+barchar 只显示最后一个柱状图

[大帅比]

出现的问题为我有三张页面，但是柱状图只有最后一个有 for循环的时候，我是调用的AsyncTask，详情如下：
private class chartTask extends AsyncTask<Integer, Integer, BarData> {
@Override
protected void onPreExecute() {

}

@Override
protected BarData doInBackground(Integer... arg0) {
// TODO Auto-generated method stub
ArrayList<BarEntry> yVals1 = new ArrayList<BarEntry>();
// for (int i = 0; i < 7; i++) {
// float mult = (30 + 1);
// float val1 = (float) (Math.random() * mult) + mult / 3;
// yVals1.add(new BarEntry((int) val1, i));
// }
yVals1.add(new BarEntry(bean.getFriday(), 0));
yVals1.add(new BarEntry(bean.getMonday(), 1));
yVals1.add(new BarEntry(bean.getSaturday(), 2));
yVals1.add(new BarEntry(bean.getSunday(), 3));
yVals1.add(new BarEntry(bean.getThursday(), 4));
yVals1.add(new BarEntry(bean.getTuesday(), 5));
yVals1.add(new BarEntry(bean.getWednesday(), 6));
ArrayList<String> xVals = new ArrayList<String>();
xVals.add("日");
xVals.add("一");
xVals.add("二");
xVals.add("三");
xVals.add("四");
xVals.add("五");
xVals.add("六");

BarDataSet set1 = new BarDataSet(yVals1, "Data Set");
set1.setColors(ColorTemplate.createColors(context,
ColorTemplate.VORDIPLOM_COLORS));

ArrayList<BarDataSet> dataSets = new ArrayList<BarDataSet>();
dataSets.add(set1);

BarData data = new BarData(xVals, dataSets);
return data;
}

@Override
protected void onPostExecute(BarData result) {
// TODO Auto-generated method stub
mSaltChart.setData(result);
mSaltChart.invalidate();
super.onPostExecute(result);
}

}

我想要的效果是每个页面都有柱状图，我只要填充一下数据