第十三篇、评分控件（星星、心形等等）

简介：

　　在很多电商类的应用，完成订单后，都会有一个给订单评分的功能，因此我也自定义一个，在此之前，没有小数的时候，还稍微好处理一下。

实现原理：

　　将前景色的view放到最上层，然后更加要显示的比例，设置前景色view的宽度。

代码示例：

.h

#import <UIKit/UIKit.h>

@interface MarkView : UIView


@property (nonatomic, assign)CGFloat scorePercent;//0到1,评分

/**
@brief 
@param frame 该控件的大小
@param numberOfStar 最大的星星数
*/
- (instancetype)initWithFrame:(CGRect)frame numberOfStars:(NSInteger)numberOfStar;

@end

.m

#import "MarkView.h"

#define FOREGROUND_STAR_IMAGE_NAME @"star5"
#define BACKGROUND_STAR_IMAGE_NAME @"star0"
#define DEFALUT_STAR_NUMBER 5

@interface MarkView   ()
@property (nonatomic, strong) UIView *foregroundStarView;
@property (nonatomic, strong) UIView *backgroundStarView;
@property (nonatomic, assign) NSInteger numberOfStars;
@end

@implementation MarkView

- (instancetype)initWithFrame:(CGRect)frame
{
    return [self initWithFrame:frame numberOfStars:DEFALUT_STAR_NUMBER];
}

- (instancetype)initWithFrame:(CGRect)frame numberOfStars:(NSInteger)numberOfStar
{
    if (self = [super initWithFrame:frame]) {
        _numberOfStars = numberOfStar;
        [self buildDataAndUI];
    }
    return self;
}

- (void)buildDataAndUI
{
    _scorePercent = 1;
    self.foregroundStarView = [self createStarViewWithImage:FOREGROUND_STAR_IMAGE_NAME];
    self.backgroundStarView = [self createStarViewWithImage:BACKGROUND_STAR_IMAGE_NAME];
    
    [self addSubview:self.backgroundStarView];
    [self addSubview:self.foregroundStarView];
}

- (UIView *)createStarViewWithImage:(NSString *)imageName
{
    UIView *view = [[UIView alloc] initWithFrame:self.bounds];
    view.clipsToBounds = YES;
    view.backgroundColor = [UIColor clearColor];
    for (int i = 0; i < self.numberOfStars; i++) {
        UIImageView *imgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
        imgView.frame = CGRectMake(i * self.bounds.size.width / self.numberOfStars, 0, self.bounds.size.width / self.numberOfStars, self.bounds.size.height );
        imgView.contentMode = UIViewContentModeScaleAspectFit;
        [view addSubview:imgView];
    }
    return view;
}

- (void)setScorePercent:(CGFloat)scorePercent
{
    if (_scorePercent == scorePercent) {
        return;
    }
    if (scorePercent < 0) {
        _scorePercent = 0;
        
    } else if (scorePercent > 1) {
        _scorePercent = 1;
    } else {
        _scorePercent = scorePercent;
    }
    self.foregroundStarView.frame = CGRectMake(0,0,self.bounds.size.width * self.scorePercent , self.bounds.size.height);
}

@end