IOS跑马灯效果，实现文字水平无间断滚动

ViewController.h

 #import <UIKit/UIKit.h>

 @interface ViewController : UIViewController{
     NSTimer           *timer;
     UIScrollView      *scrollViewText;
 }

 @property (nonatomic ,strong) NSArray *arrData;

 @end

ViewController.m

 //
 //  ViewController.m
 //  跑马灯文字广告
 //
 //  Created by Time.X on 16/2/15.
 //  Copyright © 2016年 Time.X. All rights reserved.
 //

 #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"   :@"",
                               @"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"   :@,
                               @"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"    :@,
                               @"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(, , 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 offsetX =  ,i = , h = ;

         //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) / ,
                                                                 K_MAIN_VIEW_SCROLLER_LABLE_WIDTH,
                                                                 h)];
             [labText setFont:[UIFont systemFontOfSize:]];
             [labText setTextColor:[UIColor whiteColor]];
             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, )];
     }
 }

 //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 *  animations:^{
         CGRect rect;
         CGFloat offsetX = 0.0;

         for (UILabel *lab in scrollViewText.subviews) {

             rect = lab.frame;
             offsetX = rect.origin.x - K_MAIN_VIEW_SCROLLER_SPACE;
             if (offsetX < -K_MAIN_VIEW_SCROLLER_LABLE_WIDTH)
                 offsetX = startX;

             lab.frame = CGRectMake(offsetX, rect.origin.y, rect.size.width, rect.size.height);
         }

         NSLog(@"offsetX:%f",offsetX);

     }];

 }

 @end