使用：
_chartView =[[LineChartView alloc]initWithFrame:CGRectMake(10, 0, ScreenWidth -20, SCREEN_HEIGHT - 200)];
[self.view addSubview:_chartView];
_chartView.delegate = self;
_chartView.chartDescription.enabled = NO;
_chartView.dragEnabled = YES;
[_chartView setScaleEnabled:NO];
_chartView.pinchZoomEnabled = NO;
_chartView.drawGridBackgroundEnabled = YES;
_chartView.xAxis.gridLineDashLengths = @[@10.0, @10.0];
_chartView.xAxis.gridLineDashPhase = 0.f;
//Y轴设置
ChartYAxis *leftAxis = _chartView.leftAxis;
[leftAxis removeAllLimitLines];
leftAxis.axisMaximum = 120.0; //最大值
leftAxis.axisMinimum = -0.0; //最小值
leftAxis.gridLineDashLengths = @[@5.f, @5.f];
leftAxis.drawZeroLineEnabled = NO;
leftAxis.drawLimitLinesBehindDataEnabled = YES;
leftAxis.inverted = NO;//是否翻转
//Y轴上数据格式
leftAxis.valueFormatter = [[SymbolsValueFormatter alloc]init];
leftAxis.labelPosition = YAxisLabelPositionOutsideChart;//label位置
leftAxis.labelTextColor = [UIColor blackColor];//文字颜色
leftAxis.labelFont = [UIFont systemFontOfSize:10.0f];//文字字体
leftAxis.gridColor = [UIColor grayColor];//网格线颜色
leftAxis.gridAntialiasEnabled = NO;//开启抗锯齿
_chartView.rightAxis.enabled = NO;
//X轴设置
ChartXAxis *xAxis = _chartView.xAxis;
xAxis.granularityEnabled = YES;//设置重复的值不显示
xAxis.labelPosition= XAxisLabelPositionBottom;//设置x轴数据在底部
xAxis.gridColor = [UIColor clearColor];
xAxis.labelTextColor = [UIColor blackColor];//x轴上文字颜色
xAxis.axisLineColor = [UIColor redColor];
//X轴上数据格式
xAxis.valueFormatter = [[DateValueFormatter alloc]init];
_chartView.legend.form = ChartLegendFormLine;
ChartViewPortHandler *scaleX = _chartView.viewPortHandler;
[scaleX setMinimumScaleX:1.5f];//只滑动不缩放：（系统内部默认是先缩放后滑动）及初始化时x轴就缩放1.5倍,就可以滑动了，
[_chartView animateWithXAxisDuration:2.5];
[self setDataCount:20 range:100];
//每一条线代表一条dataSet
LineChartDataSet *set1 = nil;
if (_chartView.data.dataSetCount > 0)
{
set1 = (LineChartDataSet *)_chartView.data.dataSets[0];
[set1 replaceEntries: values];
[_chartView.data notifyDataChanged];
[_chartView notifyDataSetChanged];
}
else
{
//折线数据填充
set1 = [[LineChartDataSet alloc] initWithEntries:values label:@"第一条折线"];
set1.valueFormatter =[[SetValueFormatter alloc]initWithArr:values];
set1.mode = LineChartModeCubicBezier;//平滑曲线
set1.drawIconsEnabled = NO;
set1.lineDashLengths = @[@5.f, @2.5f];
set1.highlightLineDashLengths = @[@5.f, @2.5f];
[set1 setColor:UIColor.blackColor];//线条颜色
[set1 setCircleColor:UIColor.redColor];//圆圈的颜色
set1.lineWidth = 1.0;
set1.circleRadius = 8.0;
set1.circleHoleRadius = 4;//小圆半径
set1.circleHoleColor = UIColor.blueColor;//小圆颜色
set1.drawCircleHoleEnabled = YES;//是否绘制小圆
set1.valueFont = [UIFont systemFontOfSize:9.f];//曲线上valulLabel的大小
//最下方第一条折线的设置
set1.formLineDashLengths = @[@5.f, @2.5f];
set1.formLineWidth = 1.0;
set1.formSize = 15.0;
//渐变色设置
NSArray *gradientColors = @[
(id)[ChartColorTemplates colorFromString:@"#00ff0000"].CGColor,
(id)[ChartColorTemplates colorFromString:@"#ffff0000"].CGColor
];
CGGradientRef gradient = CGGradientCreateWithColors(nil, (CFArrayRef)gradientColors, nil);
set1.fillAlpha = 1.0f;
set1.fill = [ChartFill fillWithLinearGradient:gradient angle:90.f];
set1.drawFilledEnabled = YES;
CGGradientRelease(gradient);
NSMutableArray *dataSets = [[NSMutableArray alloc] init];
[dataSets addObject:set1];
LineChartData *data = [[LineChartData alloc] initWithDataSets:dataSets];
//赋予chartView数据
_chartView.data = data;
注意点
x轴，y轴的数据自定义需要遵守协议：IChartAxisValueFormatter
折线上的数据自定义需要遵守协议：IChartValueFormatter
- (NSString *)stringForValue:(double)value axis:(ChartAxisBase *)axis
{
return [NSString stringWithFormat:@"%.f月",value];
}
上面方法返回的value就是真实值
一些使用细节
WX20190926-165333@2x.png
如上图的需求，对charts做一些定制化，简单总结下属性：
X 轴：
如果需要记录x轴文字选中的属性，需要在高亮的方法中记录LineChartRenderer中记录highLightIndex，
open override func drawHighlighted(context: CGContext, indices: [Highlight])
{
guard
let dataProvider = dataProvider,
let lineData = dataProvider.lineData
else { return }
let chartXMax = dataProvider.chartXMax
context.saveGState()
for high in indices
{
guard let set = lineData.getDataSetByIndex(high.dataSetIndex) as? ILineChartDataSet
, set.isHighlightEnabled
else { continue }
guard let e = set.entryForXValue(high.x, closestToY: high.y) else { continue }
if !isInBoundsX(entry: e, dataSet: set)
{
continue
}
highLightIndex = e.x
在绘制的时候把高亮给x轴，BarLineChartViewBase的draw方法中：
xAxisRenderer.highLightIndex = index
最后在XAxisRenderer类中 drawLabels(context: CGContext, pos: CGFloat, anchor: CGPoint)的方法中改动即可
if highLightIndex == i {
labelAttrs = [
.font: xAxis.labelHighLightFont,
.foregroundColor: xAxis.labelHighLighhtTextColor,
.paragraphStyle: paraStyle
]
}else{
labelAttrs = [
.font: xAxis.labelFont,
.foregroundColor: xAxis.labelTextColor,
.paragraphStyle: paraStyle
]
}
Y 轴的一些常用设置：
如果需要定制Y轴的分段个数，必须用以下方法设置设置，这个方法里会重新设置forceLabelsEnabled：
leftAxis setLabelCount:count force:YES];
如果需要定制Y轴文字显示的小数点，单位等等
可以继承NSNumberFormatter，遵守协议IChartAxisValueFormatter，实现方法：
//左侧Y轴单位
ValueFormatter *yFormatter =[[ValueFormatter alloc]init];
yFormatter.positiveSuffix = @"度";
}
设置小数点
yFormatter.maximumFractionDigits = 2;
yFormatter.minimumFractionDigits = 2;
}
//返回y轴的数据
- (NSString *)stringForValue:(double)value axis:(ChartAxisBase *)axis
{
return [self stringFromNumber:[NSNumber numberWithDouble:value]];
}
}
如上图，需求是Y轴6条线，需要显示3个分段，我们可以这样处理：
//返回y轴的数据
- (NSString *)stringForValue:(double)value axis:(ChartAxisBase *)axis
{
NSArray *array = axis.entries;
NSInteger index = 0;
for (NSNumber *obj in array) {
if ([obj doubleValue] == value) {
index = [array indexOfObject:obj];
break;
}
}
if (index % _ignoreCount == 0 && _ignoreCount != 0) {
return @"";
}else{
return [self stringFromNumber:[NSNumber numberWithDouble:value]];
}
}
折线的设置：
如果需要做选中的一些操作，必须打开，set.highlightEnabled = YES,否则高亮时没有的; 打开后，会出现十字线。十字线的启动属性：
//选中拐点,是否开启高亮效果(显示十字线)
set.drawVerticalHighlightIndicatorEnabled = NO;
set.drawHorizontalHighlightIndicatorEnabled = NO;
如果是多条折线，不同的折线代表的内容不同，必如一个是温度曲线，一个是水量曲线，那么就需要设置折线依赖属性：axisDependency
set.axisDependency = AxisDependencyLeft; //AxisDependencyRight 依赖左侧Y轴，依赖右侧Y轴
是否绘制曲线上的文字：
set.drawValuesEnabled = NO
圆.png
圆的副本.png
