近期公司的产品有新的需求，大概效果就如下所示：
~混合柱子~
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;
//让柱子在X轴显示全
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
}
//生成折线的数据
- (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（两根重叠的柱和折线的图）
- (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<bar1Values.count; i++) {
BarChartDataEntry *barEntry = [[BarChartDataEntry alloc] initWithX:i y:[bar1Values[i] floatValue]];
[bar1Entries addObject:barEntry];
}
for (int i=0; i<bar2Values.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。
代码已经放在GitHub上https://github.com/coolLeee/LGBarCharts，欢迎交流讨论~
