编辑：问题中的示例纯粹是为了简化它，但我不需要创建一条线，而是一条带有数据点的线。这就是我需要使用图形库的原因。数据是动态的而不是静态的。一些用户建议我为此使用图像，但这完全不是我所追求的。我试图了解如何使用“iOS-charts”库来绘制我想要的图表。
项目链接：https ://github.com/danielgindi/ios-charts
我正在使用 iOS 图表库来创建具有多条线的图形。我想要 3 行和 20 个数据点：
- 第 1 行：20 个值为 1 的值
- 第 2 行：20 个值为 2 的值
- 第 3 行：20 个值为 1 的值
我为iOS修改了github项目示例中的“ LineChart2ViewController ”示例，并没有得到我想要的结果。这就是我得到的：
怎么了：
- 线值标签是 1、2 和 3，但 y 位置似乎介于 1 和 0.4 之间。
- 我得到每个数据点的标签（我想删除标签并只显示数据）
我怎样才能做到这一点？
修改后的代码下方：
// Original code created by Daniel Cohen Gindi on 17/3/15.
//
// Copyright 2015 Daniel Cohen Gindi & Philipp Jahoda
// A port of MPAndroidChart for iOS
// Licensed under Apache License 2.0
//
// https://github.com/danielgindi/ios-charts
//
#import "LineChart2ViewController.h"
#import "ChartsDemo-Swift.h"
@interface LineChart2ViewController () <ChartViewDelegate>
@property (nonatomic, strong) IBOutlet LineChartView *chartView;
@property (nonatomic, strong) IBOutlet UISlider *sliderX;
@property (nonatomic, strong) IBOutlet UISlider *sliderY;
@property (nonatomic, strong) IBOutlet UITextField *sliderTextX;
@property (nonatomic, strong) IBOutlet UITextField *sliderTextY;
@end
@implementation LineChart2ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.title = @"Line compare";
_chartView.delegate = self;
_chartView.descriptionText = @"";
_chartView.noDataTextDescription = @"You need to provide data for the chart.";
_chartView.highlightEnabled = YES;
_chartView.dragEnabled = YES;
[_chartView setScaleEnabled:YES];
_chartView.drawGridBackgroundEnabled = NO;
_chartView.pinchZoomEnabled = YES;
_chartView.backgroundColor = [UIColor colorWithWhite:204/255.f alpha:1.f];
_chartView.legend.form = ChartLegendFormLine;
_chartView.legend.font = [UIFont fontWithName:@"HelveticaNeue-Light" size:11.f];
_chartView.legend.textColor = UIColor.whiteColor;
_chartView.legend.position = ChartLegendPositionBelowChartLeft;
ChartXAxis *xAxis = _chartView.xAxis;
xAxis.labelFont = [UIFont systemFontOfSize:12.f];
xAxis.labelTextColor = UIColor.whiteColor;
xAxis.drawGridLinesEnabled = NO;
xAxis.drawAxisLineEnabled = NO;
xAxis.spaceBetweenLabels = 1.0;
ChartYAxis *leftAxis = _chartView.leftAxis;
leftAxis.labelTextColor = [UIColor colorWithRed:51/255.f green:181/255.f blue:229/255.f alpha:1.f];
leftAxis.customAxisMax = 3;
leftAxis.drawGridLinesEnabled = YES;
ChartYAxis *rightAxis = _chartView.rightAxis;
rightAxis.labelTextColor = UIColor.redColor;
rightAxis.customAxisMax = 20.0;
rightAxis.startAtZeroEnabled = NO;
rightAxis.customAxisMin = 0.0;
rightAxis.drawGridLinesEnabled = NO;
[rightAxis setEnabled:NO];
[self setDataCount:20 range:4];
[_chartView animateWithXAxisDuration:2.5];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)setDataCount:(int)count range:(double)range
{
NSMutableArray *xVals = [[NSMutableArray alloc] init];
for (int i = 0; i < count; i++)
{
[xVals addObject:[@(i) stringValue]];
}
NSMutableArray *yVals = [[NSMutableArray alloc] init];
for (int i = 0; i < count; i++)
{
//double val = (double) (arc4random_uniform(range));
double val = 1.0;
[yVals addObject:[[ChartDataEntry alloc] initWithValue:val xIndex:i]];
}
LineChartDataSet *set1 = [[LineChartDataSet alloc] initWithYVals:yVals label:@"Line 1"];
set1.axisDependency = AxisDependencyLeft;
[set1 setColor:[UIColor colorWithRed:51/255.f green:181/255.f blue:229/255.f alpha:1.f]];
[set1 setCircleColor:UIColor.whiteColor];
set1.lineWidth = 2.0;
set1.circleRadius = 3.0;
set1.fillAlpha = 65/255.0;
set1.fillColor = [UIColor colorWithRed:51/255.f green:181/255.f blue:229/255.f alpha:1.f];
set1.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
set1.drawCircleHoleEnabled = NO;
NSMutableArray *yVals2 = [[NSMutableArray alloc] init];
for (int i = 0; i < count; i++)
{
double val = 2.0;
ChartDataEntry * dataEntry = [[ChartDataEntry alloc] initWithValue:val xIndex:i];
[yVals2 addObject:dataEntry];
}
LineChartDataSet *set2 = [[LineChartDataSet alloc] initWithYVals:yVals2 label:@"Line 2"];
set2.axisDependency = AxisDependencyRight;
[set2 setColor:UIColor.redColor];
[set2 setCircleColor:UIColor.whiteColor];
set2.lineWidth = 2.0;
set2.circleRadius = 3.0;
set2.fillAlpha = 65/255.0;
set2.fillColor = UIColor.redColor;
set2.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
set2.drawCircleHoleEnabled = NO;
NSMutableArray *yVals3 = [[NSMutableArray alloc] init];
for (int i = 0; i < count; i++)
{
double val = 3.0;
[yVals3 addObject:[[ChartDataEntry alloc] initWithValue:val xIndex:i]];
}
LineChartDataSet *set3 = [[LineChartDataSet alloc] initWithYVals:yVals3 label:@"Line 3"];
set3.axisDependency = AxisDependencyRight;
[set3 setColor:UIColor.blueColor];
[set3 setCircleColor:UIColor.whiteColor];
set3.lineWidth = 2.0;
set3.circleRadius = 3.0;
set3.fillAlpha = 65/255.0;
set3.fillColor = UIColor.blueColor;
set3.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
set3.drawCircleHoleEnabled = NO;
NSMutableArray *dataSets = [[NSMutableArray alloc] init];
[dataSets addObject:set1];
[dataSets addObject:set2];
[dataSets addObject:set3];
LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSets:dataSets];
[data setValueTextColor:UIColor.whiteColor];
[data setValueFont:[UIFont systemFontOfSize:9.f]];
_chartView.data = data;
}
