本文例項為大家分享了iOS實現轉盤效果的具體程式碼，供大家參考，具體內容如下

Demo下載地址： iOS轉盤效果

功能：實現了常用的iOS轉盤效果，輪盤抽獎效果的實現，轉盤可以暫停，旋轉，已經快速旋轉抽獎，選中的效果指向正上方。

效果圖：

工程檔案目錄：

核心程式碼：

//
// ViewController.m
// 轉盤效果
//
// 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檔案

//
// WheelView.h
// 轉盤效果
//
// 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
// 轉盤效果
//
// 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;

 //載入原始大圖片
 UIImage *oriImage = [UIImage imageNamed:@"LuckyAstrology"];
 //載入原始選中的大圖片
 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,btnW,btnH);

  //按鈕正常狀態圖片
  X = i * clipW;
  //給定一張圖片擷取指定區域內的圖片
  CGImageRef clipImg = CGImageCreateWithImageInRect(oriImage.CGImage,CGRectMake(X,Y,clipW,clipH));
  [btn setImage:[UIImage imageWithCGImage:clipImg] forState:UIControlStateNormal];

  //按鈕選中狀態圖片
  CGImageRef clipSelImg = CGImageCreateWithImageInRect(oriSelImg.CGImage,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];

  //預設第一個按鈕選中
  if (i == 0) {
   [self btnClick:btn];
  }
 }
}

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

 //1.讓當前選中的按鈕取消選中
 self.selectBtn.selected = NO;
 //2.讓當前點選的按鈕成為選中狀態
 btn.selected = YES;
 //3.當前點選的按鈕成為選中狀態
 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 {

 //快速轉幾圈
 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;
 //獲取當前選中按鈕的旋轉角度
 CGFloat angle = atan2(transform.b,transform.a);

 //動畫結束時當前選中的按鈕指向最上方
 self.contentV.transform = CGAffineTransformMakeRotation(-angle);
}

@end

WheelBtn.m

//
// WheelBtn.m
// 轉盤效果
//
// 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,self.bounds.size.width,self.bounds.size.height * 0.5);

 if (CGRectContainsPoint(rect,point)) {
  // 在指定的範圍內
  return [super hitTest:point withEvent:event];
 } else {
  return nil;
 }
}
//取消按鈕高亮狀態做的事
- (void)setHighlighted:(BOOL)highlighted {


}

//返回當前按鈕中的image位置和尺寸
- (CGRect)imageRectForContentRect:(CGRect)contentRect {

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

//返回當前按鈕中的Label位置和尺寸
//- (CGRect)titleRectForContentRect:(CGRect)contentRect{
//
//}
@end

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。