iOS实现转盘效果

//
// ViewController.m
// 转盘效果
//
// Created by llkj on 2017/8/31.
// Copyright © 2017年 LayneCheung. All rights reserved.
//

#import "ViewController.h"
#import "WheelView.h"

@interface ViewController ()

@property (nonatomic, weak) WheelView *wheelV;
@end

@implementation ViewController

- (void)viewDidLoad {
 [super viewDidLoad];

 WheelView *wheelV = [WheelView wheelView];
 wheelV.center = self.view.center;
 self.wheelV = wheelV;
 [self.view addSubview:wheelV];


}

- (IBAction)rotation:(id)sender {
 [self.wheelV rotation];
}

- (IBAction)stop:(id)sender {
 [self.wheelV stop];
}

- (void)didReceiveMemoryWarning {
 [super didReceiveMemoryWarning];
 // Dispose of any resources that can be recreated.
}


@end

//
// WheelView.h
// 转盘效果
//
// Created by llkj on 2017/8/31.
// Copyright © 2017年 LayneCheung. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface WheelView : UIView

+ (instancetype)wheelView;

- (void)rotation;
- (void)stop;
@end

//
// WheelView.m
// 转盘效果
//
// Created by llkj on 2017/8/31.
// Copyright © 2017年 LayneCheung. All rights reserved.
//

#import "WheelView.h"
#import "WheelBtn.h"

#define angle2Rad(angle) ((angle) / 180.0 * M_PI)

@interface WheelView ()<CAAnimationDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *contentV;

@property (nonatomic, weak) UIButton *selectBtn;

@property (nonatomic, strong) CADisplayLink *link;
@end

@implementation WheelView

- (CADisplayLink *)link {

 if (_link == nil) {
 CADisplayLink *link = [CADisplayLink displayLinkWithTarget:self selector:@selector(update)];
 [link addToRunLoop:[NSRunLoop mainRunLoop] fORMode:NSDefaultRunLoopMode];
 _link = link;
 }
 return _link;
}
+ (instancetype)wheelView {

 return [[[NSBundle mainBundle] loadNibNamed:@"WheelView" owner:nil options:nil] lastObject];
}


- (instancetype)initWithFrame:(CGRect)frame
{
 self = [super initWithFrame:frame];
 if (self) {
 self = [[[NSBundle mainBundle] loadNibNamed:@"WheelView" owner:nil options:nil] lastObject];
 }
 return self;
}

- (void)awakeFromNib {
 [super awakeFromNib];

 CGFloat btnW = 68;
 CGFloat btnH = 143;
 CGFloat angle = 0;

 //加载原始大图片
 UIImage *oriImage = [UIImage imageNamed:@"LuckyAstrology"];
 //加载原始选中的大图片
 UIImage *oriSelImg = [UIImage imageNamed:@"LuckyAstrologyPressed"];

 CGFloat X = 0;
 CGFloat Y = 0;
 CGFloat sacle = [UIScreen mainScreen].scale;
 CGFloat clipW = oriImage.size.width / 12.0 * sacle;
 CGFloat clipH = oriImage.size.height * sacle;

 for (int i = 0; i < 12; i ++) {

 WheelBtn *btn = [WheelBtn buttonWithType:UIButtonTypeCustom];
 btn.bounds = CGRectMake(0, 0, btnW, btnH);

 //按钮正常状态图片
 X = i * clipW;
 //给定一张图片截取指定区域内的图片
 CGImageRef clipImg = CGImageCreateWithImageInRect(oriImage.CGImage, CGRectMake(X, Y, clipW, clipH));
 [btn setImage:[UIImage imageWithCGImage:clipImg] forState:UIControlStateNormal];

 //按钮选中状态图片
 CGImageRef clipSelImg = CGImageCreateWithImageInRect(oriSelImg.CGImage, CGRectMake(X, Y, clipW, clipH));
 [btn setImage:[UIImage imageWithCGImage:clipSelImg] forState:UIControlStateSelected];

 [btn setBackgroundImage:[UIImage imageNamed:@"LuckyRototeSelected"] forState:UIControlStateSelected];
 btn.layer.anchorPoint = CGPointMake(0.5, 1);
 btn.layer.position = CGPointMake(self.bounds.size.width * 0.5, self.bounds.size.height * 0.5);

 btn.transform = CGAffineTransformMakeRotation(angle2Rad(angle));
 angle += 30;

 [btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
 [self.contentV addSubview:btn];

 //默认第一个按钮选中
 if (i == 0) {
  [self btnClick:btn];
 }
 }
}

- (void)btnClick:(UIButton *)btn {

 //1.让当前选中的按钮取消选中
 self.selectBtn.selected = NO;
 //2.让当前点击的按钮成为选中状态
 btn.selected = YES;
 //3.当前点击的按钮成为选中状态
 self.selectBtn = btn;


}
- (void)rotation {

 self.link.paused = NO;
}

- (void)stop {

 self.link.paused = YES;
}

- (void)update {

 self.contentV.transform = CGAffineTransformRotate(self.contentV.transform, M_PI / 300.0);

}

- (IBAction)start:(id)sender {

 //快速转几圈
 CABasicAnimation *anim = [CABasicAnimation animation];
 anim.keyPath = @"transform.rotation";
 anim.toValue = @(M_PI * 4);
 anim.duration = 0.5;
 anim.repeatCount = 1;
 anim.delegate = self;
 [self.contentV.layer addAnimation:anim forKey:nil];

}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {

 CGAffineTransform transform = self.selectBtn.transform;
 //获取当前选中按钮的旋转角度
 CGFloat angle = atan2(transform.b, transform.a);

 //动画结束时当前选中的按钮指向最上方
 self.contentV.transform = CGAffineTransformMakeRotation(-angle);
}

@end

//
// WheelBtn.m
// 转盘效果
//
// Created by llkj on 2017/8/31.
// Copyright © 2017年 LayneCheung. All rights reserved.
//

#import "WheelBtn.h"

@implementation WheelBtn

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {

 CGRect rect = CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height * 0.5);

 if (CGRectContainsPoint(rect, point)) {
 // 在指定的范围内
 return [super hitTest:point withEvent:event];
 } else {
 return nil;
 }
}
//取消按钮高亮状态做的事
- (void)setHighlighted:(BOOL)highlighted {


}

//返回当前按钮中的image位置和尺寸
- (CGRect)imageRectForContentRect:(CGRect)contentRect {

 return CGRectMake((contentRect.size.width - 40) *0.5, 20, 40, 48);
}

//返回当前按钮中的Label位置和尺寸
//- (CGRect)titleRectForContentRect:(CGRect)contentRect{
//
//}
@end