iOS如何简单实现绘制爱心?

灵感来源于前端css画红心的原理

上代码

#import <uikit/uikit.h>
/**
    灵感来自于前端css画红心的原理: 一个正方形 + 两个圆 + 整体旋转一定的角度
*/

ns_assume_nonnull_begin
ib_designable
@interface wgbheartview : uiview
//❤心有多大?
@property (nonatomic,assign) ibinspectable cgfloat heartsize;
//❤心的颜色?
@property (nonatomic,strong) ibinspectable uicolor *heartcolor;
@end
ns_assume_nonnull_end


#import "wgbheartview.h"

@interface wgbheartview()

@property (nonatomic,strong) uiview *bottomview;
@property (nonatomic,strong) uiview *leftview;
@property (nonatomic,strong) uiview *rightview;

@end

@implementation wgbheartview

- (instancetype)initwithframe:(cgrect)frame
{
    self = [super initwithframe:frame];
    if (self) {
        [self initconfig];
    }
    return self;
}

- (instancetype)initwithcoder:(nscoder *)coder
{
    self = [super initwithcoder:coder];
    if (self) {
        [self initconfig];
    }
    return self;
}

- (void)initconfig{
        //默认值
    self.heartsize = 150.0;
    self.heartcolor = [uicolor redcolor];
    [self addsubview: self.bottomview];
    [self addsubview: self.leftview];
    [self addsubview: self.rightview];
    //提前旋转45度
    self.transform = cgaffinetransformmakerotation(m_pi_4);
}

//去除设置背景色 
- (void)setbackgroundcolor:(uicolor *)backgroundcolor{
    backgroundcolor = [uicolor clearcolor];
    [super setbackgroundcolor:backgroundcolor];
}

- (void)setheartsize:(cgfloat)heartsize{
    _heartsize = heartsize;
    cgfloat partsize = heartsize/3.0;
    self.bottomview.frame = cgrectmake(partsize, partsize, partsize*2 , partsize*2);
    self.leftview.frame = cgrectmake(0, partsize, partsize*2 , partsize*2);
    self.rightview.frame = cgrectmake(partsize, 0, partsize*2 , partsize*2);
    
    self.leftview.layer.cornerradius = partsize;
    self.rightview.layer.cornerradius = partsize;
}

- (void)setheartcolor:(uicolor *)heartcolor{
    _heartcolor = heartcolor;
    self.bottomview.backgroundcolor = heartcolor;
    self.leftview.backgroundcolor = heartcolor;
    self.rightview.backgroundcolor = heartcolor;
}

    ///mark:- lazy load
- (uiview *)bottomview{
    if (!_bottomview) {
        _bottomview = [[uiview alloc] initwithframe:cgrectzero];
        [self addsubview:_bottomview];
    }
    return _bottomview;
}
- (uiview *)leftview{
    if (!_leftview) {
        _leftview = [[uiview alloc] initwithframe:cgrectzero];
        [self addsubview:_leftview];
    }
    return _leftview;
}

- (uiview *)rightview{
    if (!_rightview) {
        _rightview = [[uiview alloc] initwithframe:cgrectzero];
        [self addsubview:_rightview];
    }
    return _rightview;
}

@end

简单调用如下:

    wgbheartview *heartview = [[wgbheartview alloc] initwithframe:cgrectmake(100, 100, 100 , 100)];
    heartview.heartcolor = [uicolor blackcolor];//默认颜色是红色
    heartview.heartsize = 100; //这个尺寸最好是设置与视图宽高一致 生成的爱心❤️比较规则
    [self.view addsubview: heartview];
    
    for (nsinteger i = 0; i < 6; i += 1) {
        cgfloat heartwh = 50.0f;
        cgfloat margin = 15.0f;
        wgbheartview *heartitemview = [[wgbheartview alloc] initwithframe:cgrectmake(20 + (heartwh+margin)*i,   250, heartwh , heartwh)];
        heartitemview.heartcolor = [uicolor colorwithred:arc4random()%256/255.0f green:arc4random()%256/255.0f  blue:arc4random()%256/255.0f alpha:1.0f];
        heartitemview.heartsize = heartwh;
        [self.view addsubview: heartitemview];
    }