【iOS】实现星级评分

许多App都会有评价功能，这个时候或许会需要实现星级评分，下面我们来简单的实现一个星级评分功能。

应用商店评分
淘宝星星评分

具体实现

• 导入资源
  首先我们需要将需要的图片资源导入项目中。可以直接拖入项目中也可放在Assets.xcassets里。推荐放在Assets.xcassets中。
• .m文件中的相关代码

#import <UIKit/UIKit.h>
@class XHStarRateView;
typedef void(^finishBlock)(CGFloat currentScore);
typedef NS_ENUM(NSInteger, RateStyle)
{
    WholeStar = 0, //只能整星评论
    HalfStar = 1,  //允许半星评论
    IncompleteStar = 2  //允许不完整星评论
};
@protocol XHStarRateViewDelegate <NSObject>
-(void)starRateView:(XHStarRateView *)starRateView currentScore:(CGFloat)currentScore;
@end
@interface XHStarRateView : UIView
@property (nonatomic,assign)BOOL isAnimation;       //是否动画显示，默认NO
@property (nonatomic,assign)RateStyle rateStyle;    //评分样式    默认是WholeStar
@property (nonatomic,assign)CGFloat currentScore;   // 当前评分：0-5  默认0
@property (nonatomic, weak) id<XHStarRateViewDelegate>delegate;
/** 
*通过代理的方法获取当前评分数currentScore 
*/
-(instancetype)initWithFrame:(CGRect)frame;
-(instancetype)initWithFrame:(CGRect)frame numberOfStars:(NSInteger)numberOfStars rateStyle:(RateStyle)rateStyle isAnination:(BOOL)isAnimation delegate:(id)delegate;
/** 
*通过Block传值的方法获取当前评分数currentScore 
*/
-(instancetype)initWithFrame:(CGRect)frame finish:(finishBlock)finish;
-(instancetype)initWithFrame:(CGRect)frame numberOfStars:(NSInteger)numberOfStars rateStyle:(RateStyle)rateStyle isAnination:(BOOL)isAnimation finish:(finishBlock)finish;
@end

• .h文件中的相关代码

#import "XHStarRateView.h"
#define ForegroundStarImage @"b27_icon_star_yellow"
#define BackgroundStarImage @"b27_icon_star_gray"
typedef void(^completeBlock)(CGFloat currentScore);
@interface XHStarRateView()
@property (nonatomic, strong) UIView *foregroundStarView;
@property (nonatomic, strong) UIView *backgroundStarView;
@property (nonatomic, assign) NSInteger numberOfStars;
@property (nonatomic,strong)completeBlock complete;
@end
@implementation XHStarRateView
#pragma mark - 代理方式
-(instancetype)initWithFrame:(CGRect)frame{
    if (self = [super initWithFrame:frame]) {
        _numberOfStars = 5;
        _rateStyle = WholeStar;
        [self createStarView];
    }
    return self;
}
-(instancetype)initWithFrame:(CGRect)frame numberOfStars:(NSInteger)numberOfStars rateStyle:(RateStyle)rateStyle isAnination:(BOOL)isAnimation delegate:(id)delegate{
    if (self = [super initWithFrame:frame]) {
        _numberOfStars = numberOfStars;
        _rateStyle = rateStyle;
        _isAnimation = isAnimation;
        _delegate = delegate;
        [self createStarView];
    }
    return self;
}
#pragma mark - block方式
-(instancetype)initWithFrame:(CGRect)frame finish:(finishBlock)finish{
    if (self = [super initWithFrame:frame]) {
        _numberOfStars = 5;
        _rateStyle = WholeStar;
        _complete = ^(CGFloat currentScore){
            finish(currentScore);
        };
        [self createStarView];
    }
    return self;
}
-(instancetype)initWithFrame:(CGRect)frame numberOfStars:(NSInteger)numberOfStars rateStyle:(RateStyle)rateStyle isAnination:(BOOL)isAnimation finish:(finishBlock)finish{
    if (self = [super initWithFrame:frame]) {
        _numberOfStars = numberOfStars;
        _rateStyle = rateStyle;
        _isAnimation = isAnimation;
        _complete = ^(CGFloat currentScore){
            finish(currentScore);
        };
        [self createStarView];
    }
    return self;
}
#pragma mark - private Method
-(void)createStarView{   
    self.foregroundStarView = [self createStarViewWithImage:ForegroundStarImage];
    self.backgroundStarView = [self createStarViewWithImage:BackgroundStarImage];
    self.foregroundStarView.frame = CGRectMake(0, 0, self.bounds.size.width*_currentScore/self.numberOfStars, self.bounds.size.height);
    [self addSubview:self.backgroundStarView];
    [self addSubview:self.foregroundStarView];
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(userTapRateView:)];
    tapGesture.numberOfTapsRequired = 1;
    [self addGestureRecognizer:tapGesture];
}
-(UIView *)createStarViewWithImage:(NSString *)imageName {
    UIView *view = [[UIView alloc] initWithFrame:self.bounds];
    view.clipsToBounds = YES;
    view.backgroundColor = [UIColor clearColor];
    for (NSInteger i = 0; i < self.numberOfStars; i ++)
    {
        UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
        imageView.frame = CGRectMake(i * self.bounds.size.width / self.numberOfStars, 0, self.bounds.size.width / self.numberOfStars, self.bounds.size.height);
        imageView.contentMode = UIViewContentModeScaleAspectFit;
        [view addSubview:imageView];
    }
    return view;
}
-(void)userTapRateView:(UITapGestureRecognizer *)gesture {
    CGPoint tapPoint = [gesture locationInView:self];
    CGFloat offset = tapPoint.x;
    CGFloat realStarScore = offset / (self.bounds.size.width / self.numberOfStars);
    switch (_rateStyle) {
        case WholeStar:
        {
            self.currentScore = ceilf(realStarScore);
            break;
        }
        case HalfStar:
            self.currentScore = roundf(realStarScore)>realStarScore ? ceilf(realStarScore):(ceilf(realStarScore)-0.5);
            break;
        case IncompleteStar:
            self.currentScore = realStarScore;
            break;
        default:
            break;
    }
}
-(void)layoutSubviews {
    [super layoutSubviews];
    __weak XHStarRateView *weakSelf = self;
    CGFloat animationTimeInterval = self.isAnimation ? 0.2 : 0;
    [UIView animateWithDuration:animationTimeInterval animations:^{
        weakSelf.foregroundStarView.frame = CGRectMake(0, 0, weakSelf.bounds.size.width * weakSelf.currentScore/self.numberOfStars, weakSelf.bounds.size.height);
    }];
}
-(void)setCurrentScore:(CGFloat)currentScore {
    if (_currentScore == currentScore) {
        return;
    }
    if (currentScore < 0) {
        _currentScore = 0;
    } else if (currentScore > _numberOfStars) {
        _currentScore = _numberOfStars;
    } else {
        _currentScore = currentScore;
    }
    if ([self.delegate respondsToSelector:@selector(starRateView:currentScore:)]) {
        [self.delegate starRateView:self currentScore:_currentScore];
    } 
    if (self.complete) {
        _complete(_currentScore);
    }
    [self setNeedsLayout];
}
@end

• 效果图

  
  
• Demo下载链接
  https://github.com/huahua0809/XHStarRateView