我是一名新手ios程序员。在我的一个项目中,我需要绘制一个圆圈,其中圆圈的不同部分将填充不同的颜色。我可以绘制圆圈。但我无法确定圆圈的不同部分,并用不同的颜色填充它们。这是一个截图,以阐明我想要绘制的内容。
将不胜感激。
答案 0 :(得分:11)
您可以使用UIBezierPath
方法addArcWithCenter:radius:startAngle:endAngle:clockwise:
,您可以在其中指定半径,中心和角度。代码看起来像这样,以绿色绘制四分之一圆:
CGPoint center = CGPointMake(CGRectGetWidth(self.bounds) / 2.f, CGRectGetHeight(self.bounds) / 2.f);
CGFloat radius = center.x - 10.f;
UIBezierPath *portionPath = [UIBezierPath bezierPath];
[portionPath moveToPoint:center];
[portionPath addArcWithCenter:center radius:radius startAngle:0.f endAngle:M_PI_2 clockwise:YES];
[portionPath closePath];
[[UIColor greenColor] setFill];
[portionPath fill];
UIBezierPath *portionPath1 = [UIBezierPath bezierPath];
[portionPath1 moveToPoint:center];
[portionPath1 addArcWithCenter:center radius:radius startAngle:M_PI_2 endAngle:M_PI clockwise:YES];
[portionPath1 closePath];
[[UIColor blueColor] setFill];
[portionPath1 fill];
当然,您也可以考虑使用像CorePlot这样的库。
答案 1 :(得分:3)
我们有6个班级
CircleViewController.h,CircleViewController.m,GraphView.h,GraphView.h,CirclePart.h,CirclePart.m
<强> CirclePart.h 强>
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
@interface CirclePart : NSObject
@property (nonatomic) CGFloat startDegree;
@property (nonatomic) CGFloat endDegree;
@property (nonatomic) UIColor *partColor;
-(id)initWithStartDegree:(CGFloat)startDegree endDegree:(CGFloat)endDegree partColor:(UIColor*)partColor;
@end
<强> CirclePart.m 强>
#import "CirclePart.h"
@implementation CirclePart
-(id)initWithStartDegree:(CGFloat)startDegree endDegree:(CGFloat)endDegree partColor:(UIColor*)partColor
{
self = [super init];
if (self) {
self.startDegree = startDegree;
self.endDegree = endDegree;
self.partColor = partColor;
}
return self;
}
@end
<强> GraphView.h 强>
#import <UIKit/UIKit.h>
#import "CirclePart.h"
@interface GraphView : UIView
@property (nonatomic) CGPoint centrePoint;
@property (nonatomic) CGFloat radius;
@property (nonatomic) CGFloat lineWidth;
@property (nonatomic, strong) NSArray *circleParts;
-(id)initWithFrame:(CGRect)frame CentrePoint:(CGPoint)centrePoint radius:(CGFloat)radius lineWidth:(CGFloat)lineWidth circleParts:(NSArray*)circleParts;
@end
<强> GraphView.m 强>
#import "GraphView.h"
@implementation GraphView
-(id)initWithFrame:(CGRect)frame CentrePoint:(CGPoint)centrePoint radius:(CGFloat)radius lineWidth:(CGFloat)lineWidth circleParts:(NSArray*)circleParts
{
self = [super initWithFrame:frame];
if (self) {
self.centrePoint = centrePoint;
self.radius = radius;
self.lineWidth = lineWidth;
self.circleParts = circleParts;
}
return self;
}
- (void)drawRect:(CGRect)rect {
[self drawCircle];
}
- (void)drawCircle {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, _lineWidth);
for(CirclePart *circlePart in _circleParts)
{
CGContextMoveToPoint(context, _centrePoint.x, _centrePoint.y);
CGContextAddArc(context, _centrePoint.x , _centrePoint.y, _radius, [self radians:circlePart.startDegree], [self radians:circlePart.endDegree], 0);
CGContextSetFillColorWithColor(context, circlePart.partColor.CGColor);
CGContextFillPath(context);
}
}
-(float) radians:(double) degrees {
return degrees * M_PI / 180;
}
@end
<强> CircleViewController.h 强>
#import <UIKit/UIKit.h>
@interface CircleViewController : UIViewController
@end
<强> CircleViewController.m 强>
#import "CircleViewController.h"
#import "GraphView.h"
#import "CirclePart.h"
@interface CircleViewController ()
@end
@implementation CircleViewController
- (void)viewDidLoad {
[super viewDidLoad];
CirclePart *part1 = [[CirclePart alloc] initWithStartDegree:0 endDegree:120 partColor:[UIColor redColor]];
CirclePart *part2 = [[CirclePart alloc] initWithStartDegree:120 endDegree:250 partColor:[UIColor blueColor]];
CirclePart *part3 = [[CirclePart alloc] initWithStartDegree:250 endDegree:360 partColor:[UIColor grayColor]];
NSArray *circleParts = [[NSArray alloc] initWithObjects:part1, part2, part3, nil];
CGRect rect = CGRectMake(100, 100, 200, 200);
CGPoint circleCenter = CGPointMake(rect.size.width / 2, rect.size.height / 2);
GraphView *graphView = [[GraphView alloc] initWithFrame:rect CentrePoint:circleCenter radius:80 lineWidth:2 circleParts:circleParts];
graphView.backgroundColor = [UIColor whiteColor];
graphView.layer.borderColor = [UIColor redColor].CGColor;
graphView.layer.borderWidth = 1.0f;
[self.view addSubview:graphView];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
答案 2 :(得分:0)
这是一个简单的三角学问题。计算饼图部分所需的角度(饼图切片百分比时间360度),然后移动到中心。以适当的角度划线到圆形边缘,以圆弧角度到达饼形切片的下一侧,然后返回到中心。
或者,您可以使用CorePlot为您制作饼图。