体温上报APP——柱状图

要求：

要求每人录入15天的体温数据， 以折线图或柱状图展示个人15天的体温变化情况。

我采用的是MPAndroidChart。

一、过程

1、首先将MPAndroidChart的jar包导入工程中

2、绘制xml布局代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@mipmap/bj3">

    <com.github.mikephil.charting.charts.BarChart
        android:id="@+id/show_chart"
        android:layout_width="match_parent"
        android:layout_height="500dp"
        >

    </com.github.mikephil.charting.charts.BarChart>
</LinearLayout>

3、编写java代码

思路：

设置外观

private void setLegend() {
        Legend legend = barChart.getLegend();
        legend.setFormSize(12f); 
        legend.setTextSize(15f); 
        legend.setOrientation(Legend.LegendOrientation.HORIZONTAL); 
        legend.setHorizontalAlignment(Legend.LegendHorizontalAlignment.LEFT); 
        legend.setVerticalAlignment(Legend.LegendVerticalAlignment.BOTTOM); 
        legend.setYOffset(55f);
        legend.setXOffset(30f);
    }

设置坐标轴

private void setAxis() {
        // 设置x轴
        XAxis xAxis = barChart.getXAxis();
        xAxis.setPosition(XAxis.XAxisPosition.BOTTOM); 
        xAxis.setDrawGridLines(false); 
        xAxis.setLabelCount(list1.size());list1.size()
        xAxis.setTextSize(12f); 
        xAxis.setGranularity(1f);


        xAxis.setValueFormatter(new IAxisValueFormatter() {
            @Override
            public String getFormattedValue(float value, AxisBase axis) {
                if ((int) value < list1.size()) {
                    return list1.get((int) value);
                } else {
                    return "";
                }
            }
        });
        xAxis.setYOffset(5); 

       //设置y轴
        YAxis yAxis_right = barChart.getAxisRight();
        yAxis_right.setAxisMaximum(40f);
        yAxis_right.setAxisMinimum(35f); 
        yAxis_right.setEnabled(false); 

        YAxis yAxis_left = barChart.getAxisLeft();
        yAxis_left.setAxisMaximum(40f);
        yAxis_left.setAxisMinimum(35f);
        yAxis_left.setTextSize(15f);
    }

添加数据：

private void setData() {
        myHelper=new DatabaseHelper(this);
        SQLiteDatabase db=myHelper.getWritableDatabase();
        List<IBarDataSet> sets = new ArrayList<>();
        List<BarEntry> barEntries = new ArrayList<>();
        float[] num = new float[list1.size()];  //存放各班级正常填报的人数

        Cursor cursor = db.query("ALL_information", null, "name=?", new String[]{username}, null, null, null);//读取数据库所有信息
        if(cursor.moveToFirst()){
            float i=0;
            do{

                String date=cursor.getString(cursor.getColumnIndex("date"));
                String temperature = cursor.getString(cursor.getColumnIndex("temperature"));
                float t=Float.parseFloat(temperature);
                barEntries.add(new BarEntry(i,t));
                i++;

            }while (cursor.moveToNext());
        }
        cursor.close();

        BarDataSet barDataSet = new BarDataSet(barEntries, "每日体温"); 
        barDataSet.setValueTextColor(Color.BLACK); 
        barDataSet.setValueTextSize(15f); 
        barDataSet.setColor(Color.parseColor("#FFFF00")); 
        

        barDataSet.setValueFormatter(new IValueFormatter() {
            @Override
            public String getFormattedValue(float value, Entry entry, int dataSetIndex, ViewPortHandler viewPortHandler) {
                return value + "℃";
            }
        });

        sets.add(barDataSet);
        BarData barData = new BarData(sets);
        barData.setBarWidth(0.6f); 
        barChart.setData(barData);
        barChart.getXAxis().setLabelRotationAngle(-60);  
        barChart.setVisibleXRange(0,6); 

    }

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二、运行结果