iOS:使用贝塞尔曲线绘制图表（折线图、柱状图、饼状图）

2021-09-16 00:58:58

1.介绍：

UIBezierPath ：画贝塞尔曲线的path类

UIBezierPath定义 ： 贝赛尔曲线的每一个顶点都有两个控制点，用于控制在该顶点两侧的曲线的弧度。

曲线的定义有四个点：起始点、终止点（也称锚点）以及两个相互分离的中间点。

滑动两个中间点，贝塞尔曲线的形状会发生变化。

UIBezierPath ：对象是CGPathRef数据类型的封装，可以方便的让我们画出 矩形 、 椭圆 或者 直线和曲线的组合形状

初始化方法：

+ (instancetype)bezierPath;

//创建一个矩形

+ (instancetype)bezierPathWithRect:(CGRect)rect;

//创建圆形或者椭圆形

+ (instancetype)bezierPathWithOvalInRect:(CGRect)rect;

+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect cornerRadius:(CGFloat)cornerRadius; // rounds all corners with the same horizontal and vertical radius

+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect byRoundingCorners:(UIRectCorner)corners cornerRadii:(CGSize)cornerRadii;

+ (instancetype)bezierPathWithArcCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise;

+ (instancetype)bezierPathWithCGPath:(CGPathRef)CGPath;

2.最基本的使用方法是：

//设置描绘的起点

- (void)moveToPoint:(CGPoint)point;

//画直线

- (void)addLineToPoint:(CGPoint)point;

//画曲线

(1)绘制二次贝塞尔曲线   分别对应终点和一个控制点

- (void)addQuadCurveToPoint:(CGPoint)endPoint controlPoint:(CGPoint)controlPoint

(1)绘制三次贝塞尔曲线   分别对应终点和两个控制点

- (void)addCurveToPoint:(CGPoint)endPoint controlPoint1:(CGPoint)controlPoint1 controlPoint2:(CGPoint)controlPoint2;

//画圆弧

- (void)addArcWithCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise

3.使用贝塞尔曲线的基本步骤是：

(1）创建一个Bezier path对象。

（2）使用方法moveToPoint:去设置初始线段的起点。

（3）添加line或者curve去定义一个或者多个subpaths。

（4）改变UIBezierPath对象跟绘图相关的属性。

4.demo演示如下：

创建一个工具类，BezierCurveView，同时给它创建一个xib文件，它继承自UIView，用来专门绘制图表的画布

BezierCurveView.h

//

//  BezierCurveView.h

//  BezierCurveLineDemo

//

//  Created by mac on 16/7/20.

//  Copyright © 2016年 xiayuanquan. All rights reserved.

//

#import <UIKit/UIKit.h>

#define MARGIN            30   // 坐标轴与画布间距

#define Y_EVERY_MARGIN    20   // y轴每一个值的间隔数

// 颜色RGB

#define XYQColor(r, g, b) [UIColor colorWithRed:(r)/255.0 green:(g)/255.0 blue:(b)/255.0 alpha:1.0]

#define XYQColorRGBA(r, g, b, a) [UIColor colorWithRed:(r)/255.0 green:(g)/255.0 blue:(b)/255.0 alpha:a]

// 随机色

#define XYQRandomColor  XYQColor(arc4random_uniform(256), arc4random_uniform(256), arc4random_uniform(256))

// 线条类型

typedef NS_ENUM(NSInteger, LineType) {

    LineType_Straight, // 折线

    LineType_Curve     // 曲线

};

@interface BezierCurveView : UIView

//初始化画布

+(instancetype)initWithFrame:(CGRect)frame;

/**

 *  画折线图

 *  @param x_names      x轴值的所有值名称

 *  @param targetValues 所有目标值

 *  @param lineType     直线类型

 */

-(void)drawLineChartViewWithX_Value_Names:(NSMutableArray *)x_names TargetValues:(NSMutableArray *)targetValues LineType:(LineType) lineType;

/**

 *  画柱状图

 *  @param x_names      x轴值的所有值名称

 *  @param targetValues 所有目标值

 */

-(void)drawBarChartViewWithX_Value_Names:(NSMutableArray *)x_names TargetValues:(NSMutableArray *)targetValues;

/**

 *  画饼状图

 *  @param x_names      x轴值的所有值名称

 *  @param targetValues 所有目标值

 */

-(void)drawPieChartViewWithX_Value_Names:(NSMutableArray *)x_names TargetValues:(NSMutableArray *)targetValues;

@end

BezierCurveView.m

//

//  BezierCurveView.m

//  BezierCurveLineDemo

//

//  Created by mac on 16/7/20.

//  Copyright © 2016年 xiayuanquan. All rights reserved.

//

#import "BezierCurveView.h"

static CGRect myFrame;

@interface BezierCurveView ()

@end

@implementation BezierCurveView

//初始化画布

+(instancetype)initWithFrame:(CGRect)frame{

    BezierCurveView *bezierCurveView = [[NSBundle mainBundle] loadNibNamed:@"BezierCurveView" owner:self options:nil].lastObject;

    bezierCurveView.frame = frame;

    //背景视图

    UIView *backView = [[UIView alloc] initWithFrame:CGRectMake(, , frame.size.width, frame.size.height)];

    backView.backgroundColor = XYQColor(, , );

    [bezierCurveView addSubview:backView];

    myFrame = frame;

    return bezierCurveView;

}

/**

 *  画坐标轴

 */

-(void)drawXYLine:(NSMutableArray *)x_names{

    UIBezierPath *path = [UIBezierPath bezierPath];

    //1.Y轴、X轴的直线

    [path moveToPoint:CGPointMake(MARGIN, CGRectGetHeight(myFrame)-MARGIN)];

    [path addLineToPoint:CGPointMake(MARGIN, MARGIN)];

    [path moveToPoint:CGPointMake(MARGIN, CGRectGetHeight(myFrame)-MARGIN)];

    [path addLineToPoint:CGPointMake(MARGIN+CGRectGetWidth(myFrame)-*MARGIN, CGRectGetHeight(myFrame)-MARGIN)];

    //2.添加箭头

    [path moveToPoint:CGPointMake(MARGIN, MARGIN)];

    [path addLineToPoint:CGPointMake(MARGIN-, MARGIN+)];

    [path moveToPoint:CGPointMake(MARGIN, MARGIN)];

    [path addLineToPoint:CGPointMake(MARGIN+, MARGIN+)];

    [path moveToPoint:CGPointMake(MARGIN+CGRectGetWidth(myFrame)-*MARGIN, CGRectGetHeight(myFrame)-MARGIN)];

    [path addLineToPoint:CGPointMake(MARGIN+CGRectGetWidth(myFrame)-*MARGIN-, CGRectGetHeight(myFrame)-MARGIN-)];

    [path moveToPoint:CGPointMake(MARGIN+CGRectGetWidth(myFrame)-*MARGIN, CGRectGetHeight(myFrame)-MARGIN)];

    [path addLineToPoint:CGPointMake(MARGIN+CGRectGetWidth(myFrame)-*MARGIN-, CGRectGetHeight(myFrame)-MARGIN+)];

    //3.添加索引格

    //X轴

    for (int i=; i<x_names.count; i++) {

        CGFloat X = MARGIN + MARGIN*(i+);

        CGPoint point = CGPointMake(X,CGRectGetHeight(myFrame)-MARGIN);

        [path moveToPoint:point];

        [path addLineToPoint:CGPointMake(point.x, point.y-)];

    }

    //Y轴（实际长度为200,此处比例缩小一倍使用）

    for (int i=; i<; i++) {

        CGFloat Y = CGRectGetHeight(myFrame)-MARGIN-Y_EVERY_MARGIN*i;

        CGPoint point = CGPointMake(MARGIN,Y);

        [path moveToPoint:point];

        [path addLineToPoint:CGPointMake(point.x+, point.y)];

    }

    //4.添加索引格文字

    //X轴

    for (int i=; i<x_names.count; i++) {

        CGFloat X = MARGIN +  + MARGIN*i;

        UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(X, CGRectGetHeight(myFrame)-MARGIN, MARGIN, )];

        textLabel.text = x_names[i];

        textLabel.font = [UIFont systemFontOfSize:];

        textLabel.textAlignment = NSTextAlignmentCenter;

        textLabel.textColor = [UIColor blueColor];

        [self addSubview:textLabel];

    }

    //Y轴

    for (int i=; i<; i++) {

        CGFloat Y = CGRectGetHeight(myFrame)-MARGIN-Y_EVERY_MARGIN*i;

        UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(, Y-, MARGIN, )];

        textLabel.text = [NSString stringWithFormat:@"%d",*i];

        textLabel.font = [UIFont systemFontOfSize:];

        textLabel.textAlignment = NSTextAlignmentCenter;

        textLabel.textColor = [UIColor redColor];

        [self addSubview:textLabel];

    }

    //5.渲染路径

    CAShapeLayer *shapeLayer = [CAShapeLayer layer];

    shapeLayer.path = path.CGPath;

    shapeLayer.strokeColor = [UIColor blackColor].CGColor;

    shapeLayer.fillColor = [UIColor clearColor].CGColor;

    shapeLayer.borderWidth = 2.0;

    [self.subviews[].layer addSublayer:shapeLayer];

}

/**

 *  画折线图

 */

-(void)drawLineChartViewWithX_Value_Names:(NSMutableArray *)x_names TargetValues:(NSMutableArray *)targetValues LineType:(LineType) lineType{

    //1.画坐标轴

    [self drawXYLine:x_names];

    //2.获取目标值点坐标

    NSMutableArray *allPoints = [NSMutableArray array];

    for (int i=; i<targetValues.count; i++) {

        CGFloat doubleValue = *[targetValues[i] floatValue]; //目标值放大两倍

        CGFloat X = MARGIN + MARGIN*(i+);

        CGFloat Y = CGRectGetHeight(myFrame)-MARGIN-doubleValue;

        CGPoint point = CGPointMake(X,Y);

        UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(point.x-, point.y-, 2.5, 2.5) cornerRadius:2.5];

        CAShapeLayer *layer = [CAShapeLayer layer];

        layer.strokeColor = [UIColor purpleColor].CGColor;

        layer.fillColor = [UIColor purpleColor].CGColor;

        layer.path = path.CGPath;

        [self.subviews[].layer addSublayer:layer];

        [allPoints addObject:[NSValue valueWithCGPoint:point]];

    }

    //3.坐标连线

    UIBezierPath *path = [UIBezierPath bezierPath];

    [path moveToPoint:[allPoints[] CGPointValue]];

    CGPoint PrePonit;

    switch (lineType) {

        case LineType_Straight: //直线

            for (int i =; i<allPoints.count; i++) {

                CGPoint point = [allPoints[i] CGPointValue];

                [path addLineToPoint:point];

            }

            break;

        case LineType_Curve:   //曲线

            for (int i =; i<allPoints.count; i++) {

                if (i==) {

                    PrePonit = [allPoints[] CGPointValue];

                }else{

                    CGPoint NowPoint = [allPoints[i] CGPointValue];

                    [path addCurveToPoint:NowPoint controlPoint1:CGPointMake((PrePonit.x+NowPoint.x)/, PrePonit.y) controlPoint2:CGPointMake((PrePonit.x+NowPoint.x)/, NowPoint.y)]; //三次曲线

                    PrePonit = NowPoint;

                }

            }

            break;

    }

    CAShapeLayer *shapeLayer = [CAShapeLayer layer];

    shapeLayer.path = path.CGPath;

    shapeLayer.strokeColor = [UIColor greenColor].CGColor;

    shapeLayer.fillColor = [UIColor clearColor].CGColor;

    shapeLayer.borderWidth = 2.0;

    [self.subviews[].layer addSublayer:shapeLayer];

    //4.添加目标值文字

    for (int i =; i<allPoints.count; i++) {

        UILabel *label = [[UILabel alloc] init];

        label.textColor = [UIColor purpleColor];

        label.textAlignment = NSTextAlignmentCenter;

        label.font = [UIFont systemFontOfSize:];

        [self.subviews[] addSubview:label];

        if (i==) {

            CGPoint NowPoint = [allPoints[] CGPointValue];

            label.text = [NSString stringWithFormat:@"%.0lf",(CGRectGetHeight(myFrame)-NowPoint.y-MARGIN)/];

            label.frame = CGRectMake(NowPoint.x-MARGIN/, NowPoint.y-, MARGIN, );

            PrePonit = NowPoint;

        }else{

            CGPoint NowPoint = [allPoints[i] CGPointValue];

            if (NowPoint.y<PrePonit.y) {  //文字置于点上方

                label.frame = CGRectMake(NowPoint.x-MARGIN/, NowPoint.y-, MARGIN, );

            }else{ //文字置于点下方

                label.frame = CGRectMake(NowPoint.x-MARGIN/, NowPoint.y, MARGIN, );

            }

            label.text = [NSString stringWithFormat:@"%.0lf",(CGRectGetHeight(myFrame)-NowPoint.y-MARGIN)/];

            PrePonit = NowPoint;

        }

    }

}

/**

 *  画柱状图

 */

-(void)drawBarChartViewWithX_Value_Names:(NSMutableArray *)x_names TargetValues:(NSMutableArray *)targetValues{

    //1.画坐标轴

    [self drawXYLine:x_names];

    //2.每一个目标值点坐标

    for (int i=; i<targetValues.count; i++) {

        CGFloat doubleValue = *[targetValues[i] floatValue]; //目标值放大两倍

        CGFloat X = MARGIN + MARGIN*(i+)+;

        CGFloat Y = CGRectGetHeight(myFrame)-MARGIN-doubleValue;

        UIBezierPath *path = [UIBezierPath bezierPathWithRect:CGRectMake(X-MARGIN/, Y, MARGIN-, doubleValue)];

        CAShapeLayer *shapeLayer = [CAShapeLayer layer];

        shapeLayer.path = path.CGPath;

        shapeLayer.strokeColor = [UIColor clearColor].CGColor;

        shapeLayer.fillColor = XYQRandomColor.CGColor;

        shapeLayer.borderWidth = 2.0;

        [self.subviews[].layer addSublayer:shapeLayer];

        //3.添加文字

        UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(X-MARGIN/, Y-, MARGIN-, )];

        label.text = [NSString stringWithFormat:@"%.0lf",(CGRectGetHeight(myFrame)-Y-MARGIN)/];

        label.textColor = [UIColor purpleColor];

        label.textAlignment = NSTextAlignmentCenter;

        label.font = [UIFont systemFontOfSize:];

        [self.subviews[] addSubview:label];

    }

}

/**

 *  画饼状图

 */

-(void)drawPieChartViewWithX_Value_Names:(NSMutableArray *)x_names TargetValues:(NSMutableArray *)targetValues{

    //设置圆点

    CGPoint point = CGPointMake(self.frame.size.width/,self.frame.size.height/);

    CGFloat startAngle = ;

    CGFloat endAngle ;

    CGFloat radius = ;

    //计算总数

    __block CGFloat allValue = ;

    [targetValues enumerateObjectsUsingBlock:^(NSNumber *targetNumber, NSUInteger idx, BOOL * _Nonnull stop) {

        allValue += [targetNumber floatValue];

    }];

    //画图

    for (int i =; i<targetValues.count; i++) {

        CGFloat targetValue = [targetValues[i] floatValue];

        endAngle = startAngle + targetValue/allValue**M_PI;

        //bezierPath形成闭合的扇形路径

        UIBezierPath *bezierPath = [UIBezierPath bezierPathWithArcCenter:point

                                                                   radius:radius

                                                               startAngle:startAngle                                                                 endAngle:endAngle

                                                                clockwise:YES];

        [bezierPath addLineToPoint:point];

        [bezierPath closePath];

        //添加文字

        CGFloat X = point.x + *cos(startAngle+(endAngle-startAngle)/) - ;

        CGFloat Y = point.y + *sin(startAngle+(endAngle-startAngle)/) - ;

        UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(X, Y, , )];

        label.text = x_names[i];

        label.font = [UIFont systemFontOfSize:];

        label.textColor = XYQColor(, , );

        [self.subviews[] addSubview:label];

        //渲染

        CAShapeLayer *shapeLayer=[CAShapeLayer layer];

        shapeLayer.lineWidth = ;

        shapeLayer.fillColor = XYQRandomColor.CGColor;

        shapeLayer.path = bezierPath.CGPath;

        [self.layer addSublayer:shapeLayer];

        startAngle = endAngle;

    }

}

@end

在ViewController.m文件中测试如下：

//

//  ViewController.m

//  BezierCurveLineDemo

//

//  Created by mac on 16/7/22.

//  Copyright © 2016年 xiayuanquan. All rights reserved.

//

#import "ViewController.h"

#import "BezierCurveView.h"

#define SCREEN_W  [UIScreen mainScreen].bounds.size.width

#define SCREEN_H  [UIScreen mainScreen].bounds.size.height

@interface ViewController ()

@property (strong,nonatomic)BezierCurveView *bezierView;

@property (strong,nonatomic)NSMutableArray *x_names;

@property (strong,nonatomic)NSMutableArray *targets;

@end

@implementation ViewController

/**

 *  X轴值

 */

-(NSMutableArray *)x_names{

    if (!_x_names) {

        _x_names = [NSMutableArray arrayWithArray:@[@"语文",@"数学",@"英语",@"物理",@"化学",@"生物",@"政治",@"历史",@"地理"]];

    }

    return _x_names;

}

/**

 *  Y轴值

 */

-(NSMutableArray *)targets{

    if (!_targets) {

        _targets = [NSMutableArray arrayWithArray:@[@,@,@,@,@,@,@,@,@]];

    }

    return _targets;

}

- (void)viewDidLoad {

    [super viewDidLoad];

    //1.初始化

    _bezierView = [BezierCurveView initWithFrame:CGRectMake(, , SCREEN_W-, )];

    _bezierView.center = self.view.center;

    [self.view addSubview:_bezierView];

    //2.折线图

    [self drawLineChart];

    //3.柱状图

    //    [self drawBaseChart];

    //4.饼状图

    //    [self drawPieChart];

}

//画折线图

-(void)drawLineChart{

    //直线

    //    [_bezierView drawLineChartViewWithX_Value_Names:self.x_names TargetValues:self.targets LineType:LineType_Straight];

    //曲线

    [_bezierView drawLineChartViewWithX_Value_Names:self.x_names TargetValues:self.targets LineType:LineType_Curve];

}

//画柱状图

-(void)drawBaseChart{

    [_bezierView drawBarChartViewWithX_Value_Names:self.x_names TargetValues:self.targets];

}

//画饼状图

-(void)drawPieChart{

    [_bezierView drawPieChartViewWithX_Value_Names:self.x_names TargetValues:self.targets];

}

@end

演示截图如下：

iOS:使用贝塞尔曲线绘制图表（折线图、柱状图、饼状图） iOS:使用贝塞尔曲线绘制图表（折线图、柱状图、饼状图）

iOS:使用贝塞尔曲线绘制图表（折线图、柱状图、饼状图） iOS:使用贝塞尔曲线绘制图表（折线图、柱状图、饼状图）

下载地址：

Github：https://github.com/xiayuanquan/BezierCurveLineTest

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