iOS开发评分、打星

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评分、打星功能在很多APP中都会用到，因此自己封装了一个类实现该功能。其中分数可以为整数和小数。希望对你有所帮助。效果如下：

INTEGER_TYPE类型效果 FLOAT_TYPE类型效果

具体实现：

1.首先添加一个协议，协议中申明一个optional方法，该方法监听评分改变事件。因为有的地方只显示星星对应的分数，因此该方法为optional。

@protocol ratingViewDelegate <NSObject>
@optional
- (void)ratingView:(LHRatingView *)view score:(CGFloat)score;
@end

2.定义一个枚举，枚举里面有两种类型，INTEGER_TYPE表示评分为整数，FLOAT_TYPE表示评分为小数。

typedef NS_ENUM(NSUInteger, RatingType) {
    INTEGER_TYPE,
    FLOAT_TYPE
};

3.实现类，定义一个LHRatingView类继承自UIView，再在类上添加两个view，一个grayStarView，一个foreStarView。grayStarView上添加空心的星星，foreStarView上添加实心的星星。再在LHRatingView上添加UITapGestureRecognizer和UIPanGestureRecognizer事件，用户点击或拖动时，改变foreStarView的宽度，即可实现该功能。

    for (int i = 0; i < starNumber; i++) {
        UIImage * grayImg = [UIImage imageNamed:@"image.bundle/starGray"];
        UIImageView * grayImgView = [[UIImageView alloc]initWithFrame:CGRectMake((eachWidth+self.widDistance)*i, self.heiDistance, eachWidth, height)];
        grayImgView.image = grayImg;
        [self.grayStarView addSubview:grayImgView];

        UIImage * foreImg = [UIImage imageNamed:@"image.bundle/starFore"];
        UIImageView * foreImgView = [[UIImageView alloc]initWithFrame:CGRectMake((eachWidth+self.widDistance)*i, self.heiDistance, eachWidth, height)];
        foreImgView.image = foreImg;
        [self.foreStarView addSubview:foreImgView];
    }
        
    UITapGestureRecognizer * tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapGestureEvent:)];
    UIPanGestureRecognizer * panGesture = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panGestureEvent:)];
        
    [self addGestureRecognizer:tapGesture];
    [self addGestureRecognizer:panGesture];

注意：foreStarView的clipsToBounds属性需设置成YES。
self.foreStarView.clipsToBounds = YES;

拖动处理及事件监听：

#pragma mark - 拖动
- (void)panGestureEvent:(UIPanGestureRecognizer *)pan_
{
    
    CGPoint point = [pan_ locationInView:self];

    if (point.x < 0) {
        return;
    }
    if(_ratingType == INTEGER_TYPE){
        NSInteger count = (NSInteger)(point.x/(eachWidth+self.widDistance))+1;
        point.x = count*(eachWidth+self.widDistance);
    }
    
    [self changeStarForeViewWithPoint:point];
}

#pragma mark - 设置显示的星星
- (void)changeStarForeViewWithPoint:(CGPoint)point
{
    CGPoint p = point;
    
    if (p.x < 0) {
        return;
    }
    
    if (p.x < self.lowestScore/maxScore*CGRectGetWidth(self.frame))
    {
        p.x = self.lowestScore/maxScore*CGRectGetWidth(self.frame);
    }
    else if (p.x > self.frame.size.width)
    {
        p.x = self.frame.size.width;
    }
    
    float sc = p.x/CGRectGetWidth(self.frame);
    
    CGRect fRect = self.foreStarView.frame;
    fRect.size.width = p.x;
    self.foreStarView.frame = fRect;
    
    _score = sc*maxScore;
    
    if(_ratingType == INTEGER_TYPE){

        _score = (int)_score;
    }
    
    if(self.delegate && [self.delegate respondsToSelector:@selector(ratingView:score:)])
    {
        [self.delegate ratingView:self score:self.score];
    }
}

GitHub Address:https://github.com/yutiandesan/PlayStar
恭喜你，看完了。

第一次在这儿发表文章，若有不合理的地方，欢迎指正。