iOS实现滚动字幕的动画特效

/*初始化*/
-(instancetype)initWithFrame:(CGRect)frame textArray:(NSArray *)textArray colorArray:(NSArray *)textColorArray;

//滚动字幕数组
@property(nonatomic,strong) NSArray<NSString *> *textArray;

//字幕颜色数组
@property(nonatomic,strong) NSArray<UIColor *> *textColorArray;

//字幕背景颜色
@property(nonatomic,strong) UIColor *backgroundColorOfCanvas;

//标签背景图片
@property(nonatomic,strong) UIImage *backgroundImageOfCanvas;

//字体大小
@property(nonatomic,assign) CGFloat fontOfSize;

//定时器
@property(nonatomic,strong) NSTimer *timer;

#pragma mark - 创建scrollView内容
-(void)createContentOfScrollView{

 //创建contentView
 self.contentSize=CGSizeMake(0, self.bounds.size.height);

 //偏移量初值设为0
 self.contentOffset=CGPointMake(0, 0);

 //关闭指示条
 self.showsHorizontalScrollIndicator=NO;

 //创建label

 CGFloat labelY=0;
 CGFloat labelW=200;
 CGFloat labelH=self.bounds.size.height;

 //添加两次一样的内容，无限循环使用
 for (int j=0; j<2;j++ ) {

 for (int i=0; i<self.textArray.count; i++) {

 UILabel *textLabel=[[UILabel alloc] initWithFrame:CGRectMake(self.contentSize.width, labelY, labelW, labelH)];

 //******标签背景******
 UIImageView *labelBackGroundView=[[UIImageView alloc] initWithFrame:textLabel.frame];

 //标签背景图片
 labelBackGroundView.image=self.backgroundImageOfCanvas;

 //*****label文字******
 if (i<self.textArray.count) {
  textLabel.text=self.textArray[i];
 }else{
  textLabel.text=@"----";
 }

 //label文字颜色(判断文字颜色数组是否存有对应的颜色，没有则使用默认颜色)
 if (i<self.textColorArray.count) {
  textLabel.textColor=self.textColorArray[i];
 }else{
  //默认颜色
  textLabel.textColor=[UIColor blackColor];
 }

 //******字体大小********
 textLabel.font=[UIFont systemFontOfSize:self.fontOfSize];

 //label标签tag值
 textLabel.tag=LABEL_TAG_INIT + i + 100 * j;

 //每创建一个label在contenSize上加上一个label的宽度
 self.contentSize=CGSizeMake(self.contentSize.width+labelW, self.bounds.size.height);

 [self addSubview:labelBackGroundView];
 [self addSubview:textLabel];

 }
 }

}

 //立即启动定时器
 [timer setFireDate:[NSDate date]];

//暂停定时器
 [timer setFireDate:[NSDate distantFuture]];

//************自动滚动timer************
 NSTimer *timer=[NSTimer scheduledTimerWithTimeInterval:SCROLL_TIME_INTERVAL target:self selector:@selector(autoScroll) userInfo:nil repeats:YES];

 [[NSRunLoop mainRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];

 //立即启动定时器
 [timer setFireDate:[NSDate date]];

 self.timer=timer;

//滚动时间间隔
#define SCROLL_TIME_INTERVAL 3

//每次滚动距离
#define SCROLL_DISTANCE 100

//自动滚动
- (void)autoScroll{

 //滚动速度
 CGFloat offSet=SCROLL_DISTANCE;

 //若果字幕滚动到第二部分重复的部分则把偏移置0，设为第一部分,实现无限循环
 if (self.contentOffset.x>=self.contentSize.width / 2) {

 self.contentOffset=CGPointMake(0, 0);
 }

 //切割每次动画滚动距离

 [UIView animateWithDuration:SCROLL_TIME_INTERVAL delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
  self.contentOffset=CGPointMake(self.contentOffset.x+offSet, self.contentOffset.y);
 } completion:nil];
}