Android开发MPAndroidChart两条折线图

Android开发两条折线图效果，还是有一定难度的，难点它的起点不是坐标0的开始，还有数值上有背景图

一、思路：

用的是MPAndroidChart的BarChart

二、效果图：

在这里插入图片描述

三、关键代码：

// 联系：893151960
class TwoBarChartActivity : AppCompatActivity(){var mContext: Context? = nulloverride fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_bar_chart_two)mContext = thisval twoDataBean = UtilHelper.JsonToObject(UtilHelper.getJson(mContext!!,"two_bar.json"), TwoDataBean::class.java)setLearnBarChart(twoDataBean.studyDetail!!.memberCount!!,twoDataBean.studyDetail!!.studyHour!!)}private fun getMaxMemberCount(memberCountList:List<MemberCount>):Float{var maxMember = 0ffor (member in memberCountList){if (member.number > maxMember){maxMember = member.number.toFloat()}}return maxMember}private fun getMaxStudyHour(studyHourList:List<StudyHour>):Float{var maxMember = 0ffor (member in studyHourList){if (member.number > maxMember){maxMember = member.number}}return maxMember}private fun setLearnBarChart(memberCountList:List<MemberCount>, studyHourList:List<StudyHour>) {barChart.description.isEnabled = falsebarChart.setDrawGridBackground(false) //不显示图表网格barChart.setDrawValueAboveBar(true) //绘制值在bar上barChart.axisRight.isEnabled = true//显示右边坐标系barChart.legend.isEnabled = true//显示图例barChart.setTouchEnabled(false)//设置是否点击树状图，不允许触碰，就没法在图上拉伸barChart.isDragEnabled = false//设置是否可以拖拽，缩放//获取X轴val xAxis = barChart.xAxisxAxis.position = XAxis.XAxisPosition.BOTTOMxAxis.textSize = 10fxAxis.setDrawGridLines(false)//xAxis.setDrawAxisLine(true)xAxis.textColor = resources.getColor(R.color.c_33)xAxis.setCenterAxisLabels(true)xAxis.axisMinimum = 0f  //设置X轴的值（最小值、最大值、然后会根据设置的刻度数量自动分配刻度显示）,要设最小，最大值，避免出现最右边的柱形看不见xAxis.axisMaximum = memberCountList.size.toFloat()//granularity是x轴在图缩放时值的间隔按比例变化，设为2f,即间隔为2倍//xAxis.granularity = 1f  //默认为1fxAxis.valueFormatter = IAxisValueFormatter { value, _ -> memberCountList[Math.min(Math.max(value.toInt(), 0), memberCountList.size - 1)].day }//下面是不需要的，写上用法备用//xAxis.setLabelCount(12,true) //第二个参数表示是否平均分配 如果为true则按比例分为12个点、如果为false则适配X刻度的值来分配点，可能没有12个点//获取Y轴val leftAxis = barChart.axisLeftleftAxis.axisMinimum = 0fvar maxLeft = getMaxMemberCount(memberCountList)if (maxLeft == 0f){maxLeft = 5f}leftAxis.axisMaximum = maxLeftleftAxis.spaceTop = 20fleftAxis.granularity = 1f//绘制虚线leftAxis.enableGridDashedLine(10f, 10f, 0f)//是否绘制0所在的网格线leftAxis.setDrawZeroLine(true)leftAxis.textSize = 10fleftAxis.textColor = resources.getColor(R.color.c_33)leftAxis.setLabelCount(5, true)val rightAxis = barChart.axisRightrightAxis.axisMinimum = 0fvar maxRight = getMaxStudyHour(studyHourList)if (maxRight == 0f){maxRight = 1f}rightAxis.axisMaximum = maxRightrightAxis.spaceTop = 20frightAxis.granularity = 1f//绘制虚线rightAxis.enableGridDashedLine(10f, 10f, 0f)//是否绘制0所在的网格线rightAxis.setDrawZeroLine(true)rightAxis.textSize = 10frightAxis.textColor = resources.getColor(R.color.c_33)rightAxis.setLabelCount(5, true)//        rightAxis.valueFormatter = IAxisValueFormatter { value, _ ->
//            val mFormat = DecimalFormat("###")
//            mFormat.format(value.toDouble())
//        }//        leftAxis.valueFormatter = IAxisValueFormatter { value, _ ->
//            val mFormat = DecimalFormat("###")
//            mFormat.format(value.toDouble())
//        }//图例barChart.getLegend().isEnabled = true //如果没法控制图例和图表之间的距离，图例不显示，改为手动添加相应的view显示val  legend = barChart.getLegend()legend.setForm(Legend.LegendForm.SQUARE)legend.setTextSize(11f)//显示位置legend.setVerticalAlignment(Legend.LegendVerticalAlignment.TOP)legend.setHorizontalAlignment(Legend.LegendHorizontalAlignment.LEFT)legend.setOrientation(Legend.LegendOrientation.HORIZONTAL)//是否绘制在图表里面legend.setDrawInside(false)barChart.data = generateData(memberCountList,studyHourList)barChart.animateY(700)}//设置数据private fun generateData(memberCountList:List<MemberCount>, studyHourList:List<StudyHour>): BarData {val entries = ArrayList<BarEntry>()for (i in memberCountList.indices) {entries.add(BarEntry(i.toFloat(), memberCountList[i].number.toFloat()))}val d = BarDataSet(entries, "学习人数(单位：个)")d.color = resources.getColor(R.color.c_32c5ff)//树状图颜色d.axisDependency = YAxis.AxisDependency.LEFT//人数为整数d.setValueFormatter { value, _, _, _ ->value.toInt().toString()}val entries2 = ArrayList<BarEntry>()for (i in studyHourList.indices) {entries2.add(BarEntry(i.toFloat(), studyHourList[i].number))}val d2 = BarDataSet(entries2, "学习时长(单位：小时)")d2.color = resources.getColor(R.color.c_73deb3)//树状图颜色d2.axisDependency = YAxis.AxisDependency.RIGHTd2.setValueFormatter { value, _, _, _ ->value.toInt().toString()}val sets = ArrayList<IBarDataSet>()sets.add(d)sets.add(d2)val groupSpace = 0.3fval barSpace = 0.05f //两个柱之间间隔val barWidth = (1f-groupSpace)/sets.size -0.05f//算式要满足：(barWidth + barSpace) * barAmount + groupSpace = (0.3 + 0.05) * 2 + 0.3 = 1.00  这样才可以x坐标和柱形对齐val cd = BarData(sets)cd.setValueTextSize(8f)cd.barWidth = barWidth//设置树状图宽度cd.groupBars(0f,groupSpace, barSpace)
//
//        cd.setValueFormatter { value, _, _, _ ->
//
//            val mFormat = DecimalFormat("###")
//            mFormat.format(value.toDouble());
//        }return cd}
}