IOS实现文字水平无间断滚动

    IOS跑马灯效果，实现文字水平无间断滚动，示例代码如下：

ViewController.h

#import<uikit uikit.h="">@interface ViewController : UIViewController{    NSTimer           *timer;    UIScrollView      *scrollViewText;}@property (nonatomic ,strong) NSArray *arrData;@end</uikit>

ViewController.m

#import ViewController.h#pragma mark - Class define variable#define K_MAIN_VIEW_SCROLL_HEIGHT 80.0f#define K_MAIN_VIEW_SCROLL_TEXT_TAG 300#define K_MAIN_VIEW_TEME_INTERVAL 0.35         //计时器间隔时间(单位秒)#define K_MAIN_VIEW_SCROLLER_SPACE 20          //每次移动的距离#define K_MAIN_VIEW_SCROLLER_LABLE_WIDTH  280  //字体宽度#define K_MAIN_VIEW_SCROLLER_LABLE_MARGIN 20   //前后间隔距离@interface ViewController ()@end@implementation ViewController#pragma mark - Class property@synthesize arrData;- (void)viewDidLoad {    [super viewDidLoad];    [self initView];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}#pragma mark - Custom method//初始化数据-(void) initView{    if (!self.arrData) {        self.arrData = @[                          @{                              @newsId   :@201507070942261935,                              @newsImg  :@http://bg.fx678.com/HTMgr/upload/UpFiles/20150707/sy_2015070709395519.jpg,                              @newsTitle:@三大理由欧元任性抗跌，欧元区峰会将为希腊定调                          },                          @{                              @newsId    :@201507070929021220,                              @newsImg   :@http://bg.fx678.com/HTMgr/upload/UpFiles/20150707/sy_2015070709273545.jpg,                              @newsTitle :@欧盟峰会或现希腊转机，黄金打响1162保卫战                          },                          @{                              @newsId    :@201507070656471857,                              @newsImg   :@http://bg.fx678.com/HTMgr/upload/UpFiles/20150707/2015070706533134.jpg,                              @newsTitle :@希腊困局欧元不怕，油价服软暴跌8%                          }                      ];    }    //文字滚动    [self initScrollText];    //开启滚动    [self startScroll];}//文字滚动初始化-(void) initScrollText{    //获取滚动条    scrollViewText = (UIScrollView *)[self.view viewWithTag:K_MAIN_VIEW_SCROLL_TEXT_TAG];    if(!scrollViewText){        scrollViewText = [[UIScrollView alloc] initWithFrame.:CGRectMake(0, 0, self.view.frame.size.width, K_MAIN_VIEW_SCROLL_HEIGHT)];        scrollViewText.showsHorizontalScrollIndicator = NO;   //隐藏水平滚动条        scrollViewText.showsVerticalScrollIndicator = NO;     //隐藏垂直滚动条        scrollViewText.tag = K_MAIN_VIEW_SCROLL_TEXT_TAG;        [scrollViewText setBackgroundColor:[UIColor grayColor]];        //清除子控件        for (UIView *view in [scrollViewText subviews]) {            [view removeFromSuperview];        }        //添加到当前视图        [self.view addSubview:scrollViewText];    }    if (self.arrData) {        CGFloat ffsetX = 0 ,i = 0, h = 30;        //设置滚动文字        UILabel *labText = nil;        for (NSDictionary *dicTemp in self.arrData) {            labText = [[UILabel alloc] initWithFrame.:CGRectMake(                                                                i * (K_MAIN_VIEW_SCROLLER_LABLE_WIDTH + K_MAIN_VIEW_SCROLLER_LABLE_MARGIN),                                                                (K_MAIN_VIEW_SCROLL_HEIGHT - h) / 2,                                                                K_MAIN_VIEW_SCROLLER_LABLE_WIDTH,                                                                h)];            [labText setFont:[UIFont systemFontOfSize:18]];            [labText setTextColor:[UIColor redColor]];            labText.text = dicTemp[@newsTitle];            offsetX += labText.frame.origin.x;            //添加到滚动视图            [scrollViewText addSubview:labText];            i++;        }        //设置滚动区域大小        [scrollViewText setContentSize:CGSizeMake(offsetX, 0)];    }}//开始滚动-(void) startScroll{    if (!timer)        timer = [NSTimer scheduledTimerWithTimeInterval:K_MAIN_VIEW_TEME_INTERVAL target:self selector:@selector(setScrollText) userInfo:nil repeats:YES];    [timer fire];}//滚动处理-(void) setScrollText{    CGFloat startX = scrollViewText.contentSize.width - K_MAIN_VIEW_SCROLLER_LABLE_WIDTH - K_MAIN_VIEW_SCROLLER_LABLE_MARGIN;    [UIView animateWithDuration:K_MAIN_VIEW_TEME_INTERVAL * 2 animations:^{        CGRect rect;        CGFloat ffsetX = 0.0;        for (UILabel *lab in scrollViewText.subviews) {            rect = lab.frame;            ffsetX = rect.origin.x - K_MAIN_VIEW_SCROLLER_SPACE;            if (offsetX < -K_MAIN_VIEW_SCROLLER_LABLE_WIDTH)                ffsetX = startX;            lab.frame. = CGRectMake(offsetX, rect.origin.y, rect.size.width, rect.size.height);        }        NSLog(@offsetX:%f,offsetX);    }];}@end