ios自动滚动UILabel，跑马灯，有两种滚动方式

主要代码：

KJMarqueeLabel.h

#import 

typedef NS_ENUM(NSUInteger, KJMarqueeLabelType) {
    KJMarqueeLabelTypeLeft = 0,//向左边滚动
    KJMarqueeLabelTypeLeftRight = 1,//先向左边，再向右边滚动
};

@interface KJMarqueeLabel : UILabel
@property(nonatomic,unsafe_unretained)KJMarqueeLabelType marqueeLabelType;
@property(nonatomic,unsafe_unretained)CGFloat speed;//速度
@property(nonatomic,unsafe_unretained)CGFloat secondLabelInterval;
@property(nonatomic,unsafe_unretained)NSTimeInterval stopTime;//滚到顶的停止时间

@end

KJMarqueeLabel.m

#import "KJMarqueeLabel.h"

@interface KJMarqueeLabel (){
    NSTimer *_timer;
    UIScrollView *_scrollV;
    UILabel *_label1;
    CGSize _scrollViewCcontentSize;
    CGFloat x;
    UILabel *_label2;
    BOOL _isRight;
}
@end

@implementation KJMarqueeLabel

- (void)awakeFromNib {
    [super awakeFromNib];
    [self commonInit];
}

-(instancetype)init {
    if (self = [super init]) {
        [self commonInit];
    }
    return self;
}

- (instancetype)initWithCoder:(NSCoder *)coder
{
    self = [super initWithCoder:coder];
    if (self) {
        [self commonInit];
    }
    return self;
}

-(instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        [self commonInit];
    }
    return self;
}

-(void)commonInit{
    self.marqueeLabelType = KJMarqueeLabelTypeLeftRight;
    self.secondLabelInterval = 100;
    self.speed = 0.7f;
    self.stopTime = 1.5f;
}

-(UILabel *)comnInitLabel:(UILabel *)label {
    label = [[UILabel alloc]initWithFrame:self.bounds];
    label.text = self.text;
    label.font = self.font;
    label.textColor = self.textColor;
    label.lineBreakMode = NSLineBreakByWordWrapping;
    return label;
}

-(void)drawTextInRect:(CGRect)rect {
    for (UIView *view in self.subviews) {
        [view removeFromSuperview];
    }
    CGFloat height = self.bounds.size.height;
    CGFloat width = self.bounds.size.width;
    
    x = 0;
    _label1 = [self comnInitLabel:_label1];
    if (self.marqueeLabelType == KJMarqueeLabelTypeLeft) {
        _label2 = [self comnInitLabel:_label2];
    }
    
    CGSize size = [_label1 sizeThatFits:CGSizeMake(MAXFLOAT,height)];
    
    //如果字符串的宽度小于或等于自身的宽度
    if (size.width <= width) {
        _label1 = nil;
        _label2 = nil;
        [super drawTextInRect:rect];
        return;
    }
    
    _scrollV = [[UIScrollView alloc]initWithFrame:self.bounds];
    _scrollV.delegate = self;
    if (self.marqueeLabelType == KJMarqueeLabelTypeLeft) {
        _scrollViewCcontentSize = CGSizeMake(size.width+width+self.secondLabelInterval, size.height);
    }else {
        _scrollViewCcontentSize = CGSizeMake(size.width, size.height);
    }
    _scrollV.contentSize = _scrollViewCcontentSize;
    
    [self addSubview:_scrollV];
    
    CGRect rect1 =  _label1.frame;
    rect1.size.width = size.width;
    _label1.frame = rect1;
    [_scrollV addSubview:_label1];
    
    if (self.marqueeLabelType == KJMarqueeLabelTypeLeft) {
        CGRect rect2 =  _label2.frame;
        rect2.size.width = width;
        rect2.origin.x = size.width + self.secondLabelInterval;
        _label2.frame = rect2;
        [_scrollV addSubview:_label2];
    }
    
    [self Timer];
}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
    if (_timer) {
        [_timer invalidate];
        _timer = nil;
    }
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
    x = scrollView.contentOffset.x;
    [self Timer];
}

-(void)Timer {
    if (_timer) {
        [_timer invalidate];
        _timer = nil;
    }

    _timer = [NSTimer scheduledTimerWithTimeInterval:0.01f target:self selector:@selector(refreshMarqueeLabelFrame) userInfo:nil repeats:YES];
    [[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];
}

-(void)FistTimer {
    if (_timer) {
        [_timer invalidate];
        _timer = nil;
    }
    _timer = [NSTimer scheduledTimerWithTimeInterval:self.stopTime target:self selector:@selector(delayMethod) userInfo:nil repeats:NO];
}

-(void)dealloc {
    if (_timer) {
        [_timer invalidate];
        _timer = nil;
    }
}

-(void)delayMethod {
    [self Timer];
}

- (void)refreshMarqueeLabelFrame {
    
    if (self.marqueeLabelType == KJMarqueeLabelTypeLeft) {
        
        x += self.speed;
        if (x > _scrollViewCcontentSize.width - _scrollV.bounds.size.width) {
            [self FistTimer];
            x = 0;
        }
        [_scrollV setContentOffset:CGPointMake(x, 0)];
        
    }else {
        if (_isRight) {
            x -= self.speed;
        }else {
            x += self.speed;
        }
        
        if (x > _scrollViewCcontentSize.width - _scrollV.bounds.size.width) {
            [self FistTimer];
            _isRight = YES;
            return;
        }
        
        if (x <= 0) {
            [self FistTimer];
            _isRight = NO;
        }
        
        [_scrollV setContentOffset:CGPointMake(x, 0)];
    }
}

@end

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