iOS Charts 混合柱状图开发

近期公司的产品有新的需求，大概效果就如下所示：

我们使用的是ios-charts这个第三方，但是在网上找了一大堆也没有发现这种效果的柱状图，没办法只能自己操刀来实现了。实现过程中借鉴了安卓中的MPCharts类似效果的实现方法，话不多说，直接上代码，代码中注释已经比较清晰了，有不懂得欢迎咨询。
我是写了一个这种效果实现的工具类，在.h文件中申明方法：

/**
 两根柱子以及折线的混合显示

 @param combineChart 需要设置的CombineChartView
 @param xValues X轴的值数组，里面放字符串
 @param lineValues 折线值数组
 @param bar1Values 柱子1的值数组
 @param bar2Values 柱子2的值数组
 @param lineTitle 图例中折线的描述
 @param bar1Title 图例中柱子1的描述
 @param bar2Title 图例中柱子2的描述

 warning:由于绘制有顺序，所以绘制高柱子应该在绘制低柱子之前进行，所以bar1Values中的值要大于对应的bar2Values中的值，绘制折线应该在最后进行
 */
- (void)setCombineBarChart:(CombinedChartView *)combineChart xValues:(NSArray *)xValues lineValues:(NSArray *)lineValues bar1Values:(NSArray *)bar1Values bar2Values:(NSArray *)bar2Values lineTitle:(NSString *)lineTitle bar1Title:(NSString *)bar1Title bar2Title:(NSString *)bar2Title;

在.m文件中实现这个方法：

- (void)setCombineBarChart:(CombinedChartView *)combineChart xValues:(NSArray *)xValues lineValues:(NSArray *)lineValues bar1Values:(NSArray *)bar1Values bar2Values:(NSArray *)bar2Values lineTitle:(NSString *)lineTitle bar1Title:(NSString *)bar1Title bar2Title:(NSString *)bar2Title
{
    combineChart.descriptionText = @"";
    combineChart.pinchZoomEnabled = YES;
    combineChart.marker = [[ChartMarkerView alloc] init];
    combineChart.drawOrder = @[@0,@0,@2];//CombinedChartDrawOrderBar,CombinedChartDrawOrderLine 绘制顺序
    combineChart.doubleTapToZoomEnabled = NO;//取消双击放大
    combineChart.scaleYEnabled = NO;//取消Y轴缩放
    combineChart.dragEnabled = YES;//启用拖拽图表
    combineChart.dragDecelerationEnabled = YES;//拖拽后是否有惯性效果
    combineChart.dragDecelerationFrictionCoef = 0.9;//拖拽后惯性效果的摩擦系数(0~1)，数值越小，惯性越不明显
    combineChart.highlightPerTapEnabled = NO;//取消单击高亮显示
    combineChart.highlightPerDragEnabled = NO;//取消拖拽高亮
    ChartXAxis *xAxis = combineChart.xAxis;
    xAxis.labelPosition = XAxisLabelPositionBottom;
    xAxis.drawGridLinesEnabled = NO;
    xAxis.labelFont = [UIFont systemFontOfSize:15];
    xAxis.labelCount = xValues.count;
    xAxis.labelRotationAngle = -40;

    xAxis.valueFormatter = [[ChartIndexAxisValueFormatter alloc] initWithValues:xValues];//设置X轴显示的值

    //左侧Y轴设置
    ChartYAxis *leftAxis = combineChart.leftAxis;
    leftAxis.labelPosition = YAxisLabelPositionOutsideChart;
    leftAxis.axisMinimum = 0.0f;
    leftAxis.drawGridLinesEnabled = YES;

    float yMin = [[bar2Values valueForKeyPath:@"@min.floatValue"] floatValue]*0.9;
    float yMax = [[bar1Values valueForKeyPath:@"@max.floatValue"] floatValue]*1.1;
    leftAxis.axisMinimum = yMin;
    leftAxis.axisMaximum = yMax;

    //右侧Y轴
    ChartYAxis *rightAxis = combineChart.rightAxis;
    rightAxis.labelPosition = YAxisLabelPositionOutsideChart;
    rightAxis.drawGridLinesEnabled = NO;
    rightAxis.axisMinimum = 0;
    rightAxis.axisMaximum = 100;
    //设置图例
    ChartLegend *legend = combineChart.legend;
    legend.horizontalAlignment = ChartLegendHorizontalAlignmentLeft;
    legend.verticalAlignment = ChartLegendVerticalAlignmentBottom;
    legend.orientation = ChartLegendOrientationHorizontal;
    legend.drawInside = NO;
    legend.direction = ChartLegendDirectionLeftToRight;
    legend.form = ChartLegendFormSquare;
    legend.formSize = 12;
    //设置数据
    CombinedChartData *data = [[CombinedChartData alloc] init];
    data.lineData = [self generateLineData:lineValues lineTitle:lineTitle];
    data.barData = [self generateCombineBarData:bar1Values bar2Values:bar2Values title1:bar1Title title2:bar2Title];
    combineChart.data = data;



    xAxis.axisMinimum = data.xMin - 1.0f;
    xAxis.axisMaximum = data.xMax + 1.0f;
    combineChart.extraBottomOffset = 10;
    combineChart.extraTopOffset = 30;
    [combineChart animateWithYAxisDuration:1.0];//添加Y轴动画
}
//生成线的数据
- (LineChartData *)generateLineData:(NSArray *)lineValues lineTitle:(NSString *)lineTitle
{
    NSMutableArray *entries = [NSMutableArray array];
    for (int i = 0; i < lineValues.count; i++) {
        ChartDataEntry *entry = [[ChartDataEntry alloc] initWithX:i y:[lineValues[i] floatValue]];
        [entries addObject:entry];
    }

    LineChartDataSet *dataSet = [[LineChartDataSet alloc] initWithValues:entries label:lineTitle];
    dataSet.colors = @[[UIColor greenColor]];
    dataSet.lineWidth = 2.5f;
    dataSet.circleColors = @[[UIColor redColor]];
    dataSet.circleHoleColor = [UIColor purpleColor];
    dataSet.axisDependency = AxisDependencyRight;
    dataSet.drawValuesEnabled = YES;//不绘制线的数据

    LineChartData *lineData = [[LineChartData alloc] initWithDataSet:dataSet];
    [lineData setValueFont:[UIFont systemFontOfSize:10]];

    return lineData;
}
//生成复杂的组合柱图的数据
- (BarChartData *)generateCombineBarData:(NSArray *)bar1Values bar2Values:(NSArray *)bar2Values title1:(NSString *)bar1Title title2:(NSString *)bar2Title
{
    NSMutableArray *bar1Entries = [NSMutableArray array];
    NSMutableArray *bar2Entries = [NSMutableArray array];
    for (int i=0; i.count; i++) {
        BarChartDataEntry *barEntry = [[BarChartDataEntry alloc] initWithX:i y:[bar1Values[i] floatValue]];
        [bar1Entries addObject:barEntry];
    }
    for (int i=0; i.count; i++) {
        BarChartDataEntry *barEntry = [[BarChartDataEntry alloc] initWithX:i y:[bar2Values[i] floatValue]];
        [bar2Entries addObject:barEntry];
    }

    BarChartDataSet *dataSet1 = [[BarChartDataSet alloc]  initWithValues:bar1Entries label:bar1Title];
    dataSet1.colors = @[[UIColor grayColor]];
    dataSet1.valueColors = @[[UIColor orangeColor]];
    dataSet1.axisDependency = AxisDependencyLeft;
    dataSet1.drawValuesEnabled = NO;

    BarChartDataSet *dataSet2 = [[BarChartDataSet alloc]  initWithValues:bar2Entries label:bar2Title];
    dataSet2.colors = @[[UIColor brownColor]];
    dataSet2.valueColors = @[[UIColor orangeColor]];
    dataSet2.axisDependency = AxisDependencyLeft;
    dataSet2.drawValuesEnabled = NO;
    BarChartData *data = [[BarChartData alloc] initWithDataSets:@[dataSet1,dataSet2]];
    [data setValueFont:[UIFont systemFontOfSize:10]];
    data.barWidth = 0.9f;
    return data;
}

要使用这个工具类也很简单，在需要的控制器中引入这个工具类，实现如下方法：

- (void)createCombineBarChartView
{
    CombinedChartView *combine = [[CombinedChartView alloc] init];
    self.combineChartView = combine;
    combine.frame = CGRectMake(0, KScreenHeight/2, KScreenWidth, KScreenHeight/2);
    combine.backgroundColor = [UIColor colorWithRed:230/255.0f green:253/255.0f blue:253/255.0f alpha:1];
    [self.view addSubview:combine];

    //我自己的工具类
    BarChartsHelper *helper = [[BarChartsHelper alloc] init];
    [helper setCombineBarChart:self.combineChartView xValues:self.xStrings lineValues:@[@"30",@"10",@"50",@"30",@"60"] bar1Values:@[@"80",@"40",@"60",@"30",@"70"] bar2Values:@[@"60",@"30",@"53",@"20",@"45"] lineTitle:@"line" bar1Title:@"bar1" bar2Title:@"bar2"];
}

其中有个注意点就是：因为柱和线的绘制是有先后顺序的。所以要让bar1Values中的值大于bar2Values中对应的值，这样才不会被遮挡住。
还有设置的lineTitle、bar1Title、bar2Title都是图例中的对应的描述。
具体demo可以查看我的github：https://github.com/coolLeee/LGBarCharts