ios自动滚动UILabel，跑马灯，有两种滚动方式

主要代码：

KJMarqueeLabel.h

#import <UIKit/UIKit.h>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 = KJMarqueeLabelTypeLeft;    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 {        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) {        [super drawTextInRect:rect];        return;    }        _scrollV = [[UIScrollView alloc]initWithFrame:self.bounds];    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)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