Android之MPAndroidChart库——双柱状图，X轴显示汉字

        在《Android之MPAndroidChart库使用说明（柱状图、折线图、饼图和组合图.）》中对利用MPAndroidChart绘制柱状图、饼图、折线图和饼图的流程做了一个简单的介绍，其中双柱图的X轴只能显示数值。鉴于有X轴显示字符串的需求，这里对双柱图时X轴显示字符串的情况进行一个简单的示例介绍。

        本文继续在上篇博客的代码的基础上进行修改。主要就是修改MPChartHelper的setTwoBarChart和setTwoBarChartData两个方法，将传入的X轴数值改为string类型，设置X轴的ValueFormatter为MP库自带的IndexAxisValueFormatter。具体修改代码如下：

public static void setTwoBarChart(BarChart barChart, List<String> xAxisValue, List<Float> yAxisValue1, List<Float> yAxisValue2, String bartilte1, String bartitle2) {        barChart.getDescription().setEnabled(false);//设置描述        barChart.setPinchZoom(true);//设置按比例放缩柱状图        barChart.setExtraBottomOffset(10);        barChart.setExtraTopOffset(30);        //x坐标轴设置        XAxis xAxis = barChart.getXAxis();        xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);        xAxis.setDrawGridLines(false);        xAxis.setDrawLabels(true);        xAxis.setGranularity(1f);        xAxis.setLabelCount(xAxisValue.size());        xAxis.setCenterAxisLabels(true);//设置标签居中        xAxis.setValueFormatter(new IndexAxisValueFormatter(xAxisValue));        //y轴设置        YAxis leftAxis = barChart.getAxisLeft();        leftAxis.setPosition(YAxis.YAxisLabelPosition.OUTSIDE_CHART);        leftAxis.setDrawGridLines(false);        leftAxis.setDrawLabels(false);        leftAxis.setDrawAxisLine(false);        //设置坐标轴最大最小值        Float yMin1 = Collections.min(yAxisValue1);        Float yMin2 = Collections.min(yAxisValue2);        Float yMax1 = Collections.max(yAxisValue1);        Float yMax2 = Collections.max(yAxisValue2);        Float yMin = Double.valueOf((yMin1 < yMin2 ? yMin1 : yMin2) * 0.1).floatValue();        Float yMax = Double.valueOf((yMax1 > yMax2 ? yMax1 : yMax2) * 1.1).floatValue();        leftAxis.setAxisMaximum(yMax);        leftAxis.setAxisMinimum(yMin);        barChart.getAxisRight().setEnabled(false);        //图例设置        Legend legend = barChart.getLegend();        legend.setHorizontalAlignment(Legend.LegendHorizontalAlignment.CENTER);        legend.setVerticalAlignment(Legend.LegendVerticalAlignment.TOP);        legend.setOrientation(Legend.LegendOrientation.HORIZONTAL);        legend.setDrawInside(false);        legend.setDirection(Legend.LegendDirection.LEFT_TO_RIGHT);        legend.setForm(Legend.LegendForm.SQUARE);        legend.setTextSize(12f);        //设置柱状图数据        setTwoBarChartData(barChart, xAxisValue, yAxisValue1, yAxisValue2, bartilte1, bartitle2);        barChart.animateX(1500);//数据显示动画，从左往右依次显示        barChart.invalidate();    }    /**     * 设置柱状图数据源     */    private static void setTwoBarChartData(BarChart barChart, List<String> xAxisValue, List<Float> yAxisValue1, List<Float> yAxisValue2, String bartilte1, String bartitle2) {        float groupSpace = 0.04f;        float barSpace = 0.03f;        float barWidth = 0.45f;        // (0.45 + 0.03) * 2 + 0.04 = 1，即一个间隔为一组，包含两个柱图 -> interval per "group"        ArrayList<BarEntry> entries1 = new ArrayList<>();        ArrayList<BarEntry> entries2 = new ArrayList<>();        for (int i = 0, n = yAxisValue1.size(); i < n; ++i) {            entries1.add(new BarEntry(i, yAxisValue1.get(i)));            entries2.add(new BarEntry(i, yAxisValue2.get(i)));        }        BarDataSet dataset1, dataset2;        if (barChart.getData() != null && barChart.getData().getDataSetCount() > 0) {            dataset1 = (BarDataSet) barChart.getData().getDataSetByIndex(0);            dataset2 = (BarDataSet) barChart.getData().getDataSetByIndex(1);            dataset1.setValues(entries1);            dataset2.setValues(entries2);            barChart.getData().notifyDataChanged();            barChart.notifyDataSetChanged();        } else {            dataset1 = new BarDataSet(entries1, bartilte1);            dataset2 = new BarDataSet(entries2, bartitle2);            dataset1.setColor(Color.rgb(129, 216, 200));            dataset2.setColor(Color.rgb(181, 194, 202));            ArrayList<IBarDataSet> dataSets = new ArrayList<>();            dataSets.add(dataset1);            dataSets.add(dataset2);            BarData data = new BarData(dataSets);            data.setValueTextSize(10f);            data.setBarWidth(0.9f);            data.setValueFormatter(new IValueFormatter() {                @Override                public String getFormattedValue(float value, Entry entry, int i, ViewPortHandler viewPortHandler) {                    return StringUtils.double2String(value, 2);                }            });            barChart.setData(data);        }        barChart.getBarData().setBarWidth(barWidth);        barChart.getXAxis().setAxisMinimum(0);        // barData.getGroupWith(...) is a helper that calculates the width each group needs based on the provided parameters        barChart.getXAxis().setAxisMaximum(barChart.getBarData().getGroupWidth(groupSpace, barSpace) * xAxisValue.size() + 0);        barChart.groupBars(0, groupSpace, barSpace);    }

效果图如下