iOS抽奖转盘：概率抽奖算法 & 转盘算法 & 转盘主视图的实现思路 （完整Demo）

@interface KNTurntableView()
/**
 转盘视图
 */
@property (strong, nonatomic) SubTurntableView *turntable;

/**
 开始抽奖按钮
 */
@property (nonatomic, weak) UIButton *startButton;
/**
 点击抽奖文字视图
 */
@property (nonatomic, weak) UIImageView *textImgView;

/**
 指针视图
 */
@property (nonatomic, weak) UIImageView *needleImgView;

- (instancetype)initWithFrame:(CGRect)frame {
    return [self initWithFrame:frame ViewModel:nil];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    return [self initWithFrame:CGRectZero ViewModel:nil];
}

- (instancetype)initWithViewModel:(id)ViewModel {
    return [self initWithFrame:CGRectZero ViewModel:ViewModel];
}

- (instancetype)initWithFrame:(CGRect)frame ViewModel:(id)viewModel {
    if (self = [super initWithFrame:frame]) {
        _viewModel = viewModel;
        [self selfInit];

        [self createSubView];
        [self setupdata];
        [self bindViewModel];
    }
    return self;
}

- (void)selfInit{
//    self.backgroundColor =  k_view_backColor;
}
- (void)createSubView{
    
    
    [self turntable];
    self.turntable.luckyItemArray = _viewModel.luckyItemArray;
    [self initStartBtn];

    
}

- (void)setupdata{
}

- (void)bindViewModel{
}


- (SubTurntableView *)turntable{
    
    
    if(_turntable == nil){
        _turntable = [[SubTurntableView alloc] init];
        [self addSubview:_turntable];
        
        
        __weak __typeof__(self) weakSelf = self;

        [_turntable mas_makeConstraints:^(MASConstraintMaker *make) {
            
            make.edges.equalTo(weakSelf);
            
            
        }];
        
        [_turntable setRotaryEndTurnBlock:^{
            
            [weakSelf lunckyAnimationDidStop];
            
            
        }];
        
        

        
    }
    
    return     _turntable;
    
;
    
    

}

/**
 //1、判断用户是否可以抽奖
 //禁用按钮
 //    self.startButton.enabled = NO;

 
 //2、发起网络请求获取当前选中奖品,demo通过随机的方式获取一次index;  另外一种是根据奖品百分比进行控制

 //3、拿到当前奖品的 找到其对于的位置

 //4、让转盘转起来

 */
- (void)startAction {
    
    [self setupStartBtnState4noenable];
    
    // 方式一： 发起网络请求获取当前选中奖品,demo通过随机的方式获取一次index;

//    self.viewModel.endId = arc4random() % self.viewModel.luckyItemArray.count;
    
    // 控制中奖的方式二：另外一种是根据奖品百分比进行控制中奖概率
//    NSInteger randomNum = arc4random()%100;//控制概率
// 奖品 title A ，index下标0，中奖 概率probability80%， 就是当randomNum为0-80，返回中奖下标0
    // 为了便于理解，我们称奖品A的【随机中奖范围】 probabilityRange为0-80
    //
    
    // 根据randomNum，确定中奖奖品
    KNTurntableViewModel *tmp = [KNTurntableViewModel getMbyprobabilityRangeWithArr:self.viewModel.luckyItemArray];
    
    //    return nil;// 谢谢参与

    
    if(tmp){
        self.viewModel.endId = tmp.index;

    }else{
        
        self.viewModel.endId = 0;//  谢谢参与

    }
    
    
    [self turntableRotate:self.viewModel.endId];
    
}

- (void)lunckyAnimationDidStop {
    
    self.startButton.enabled = YES;
    
    self.textImgView.image = [UIImage imageNamed:@"lottery_state_start"];
    self.needleImgView.image = [UIImage imageNamed:@"lottery_start_needle_enable"];

    NSLog(@"============????????============:%ld",self.viewModel.endId);
    
    
    KNTurntableViewModel *model = self.viewModel.luckyItemArray[self.viewModel.endId];
    
    
    NSLog(@"============????????============:%@",model.title);
    
        //抽奖结束 弹出奖品
    KNPrizePopView *popView = [KNPrizePopView new];
    
    KNActivityPrizeModel *m = [KNActivityPrizeModel new];
    
    m.icon = model.icon;
    m.prizeName =model.title;
    m.winnerNum = [@1 description];
    
    
    
        [popView showWithModel:m];
    
        popView.popShareBlock = ^{
            NSLog(@"分享按钮点击了");
        };

    
}

#import "KNTurntableViewModel.h"
#import <UIKit/UIKit.h>
#define D2R(degrees) ((M_PI * degrees) / 180)
@interface SubTurntableView : UIView
/**
 奖品数据
 */
@property (nonatomic, strong) NSArray<KNTurntableViewModel *> *luckyItemArray;


-(void)animationWithSelectonIndex:(NSInteger)index;


//结束旋转
@property (nonatomic, copy) void (^rotaryEndTurnBlock)(void);