iOS实现文字水平无间断滚动效果

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

//// ViewController.m// 滚动//#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 20.0f       //每次移动的距离#define K_MAIN_VIEW_SCROLLER_LABLE_WIDTH   18.0f  //单个字符宽度(与你设置的字体大小一致)#define K_MAIN_VIEW_SCROLLER_LABLE_MARGIN  20.0f  //前后间隔距离#define K_MAIN_VIEW_SCROLLER_SLEEP_INTERVAL 1    //停留时间  @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, 80, 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.scrollEnabled = NO;          //禁用手动滑动     //横竖屏自适应    scrollViewText.autoresizingMask = UIViewAutoresizingFlexibleWidth;    scrollViewText.tag = K_MAIN_VIEW_SCROLL_TEXT_TAG;    [scrollViewText setBackgroundColor:[UIColor grayColor]];     //给滚动视图添加事件    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollerViewClick:)];    [scrollViewText addGestureRecognizer:tapGesture];     //添加到当前视图    [self.view addSubview:scrollViewText];  }else{    //清除子控件    for (UIView *view in [scrollViewText subviews]) {      [view removeFromSuperview];    }  }   if (self.arrData) {     CGFloat offsetX = 0 ,i = 0, h = 30;     //设置滚动文字    UIButton *btnText = nil;    NSString *strTitle = [[NSString alloc] init];     for (NSDictionary *dicTemp in self.arrData) {       strTitle = dicTemp[@"newsTitle"];       btnText = [UIButton buttonWithType:UIButtonTypeCustom];      [btnText setFrame:CGRectMake([self getTitleLeft:i],                     (K_MAIN_VIEW_SCROLL_HEIGHT - h) / 2,                     strTitle.length * K_MAIN_VIEW_SCROLLER_LABLE_WIDTH,                     h)];       [btnText setTitleColor:[UIColor redColor] forState:UIControlStateNormal];      [btnText setTitle:strTitle forState:UIControlStateNormal];       //横竖屏自适应      btnText.autoresizingMask = UIViewAutoresizingFlexibleWidth;      offsetX += btnText.frame.origin.x;       //设置为 NO,否则无法响应点击事件      btnText.userInteractionEnabled = NO;       //添加到滚动视图      [scrollViewText addSubview:btnText];       i++;    }     //设置滚动区域大小    [scrollViewText setContentSize:CGSizeMake(offsetX, 0)];  }}  #pragma mark - 滚动处理//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{   [UIView animateWithDuration:K_MAIN_VIEW_TEME_INTERVAL * 2 animations:^{    CGRect rect;    CGFloat offsetX = 0.0,width = 0.0;     for (UIButton *btnText in scrollViewText.subviews) {       rect = btnText.frame;      offsetX = rect.origin.x - K_MAIN_VIEW_SCROLLER_SPACE;      width = [btnText.titleLabel.text length] * K_MAIN_VIEW_SCROLLER_LABLE_WIDTH;       btnText.frame = CGRectMake(offsetX, rect.origin.y, rect.size.width, rect.size.height);       NSLog(@"offsetX:%f",offsetX);    }     if (offsetX < -width){      [UIView setAnimationsEnabled:NO];      [self initScrollText];    }else      [UIView setAnimationsEnabled:YES];  }]; }  #pragma mark - 动态获取左边位置-(float) getTitleLeft:(CGFloat) i {  float left = i * K_MAIN_VIEW_SCROLLER_LABLE_MARGIN;   if (i > 0) {    for (int j = 0; j < i; j ++) {      left += [[self.arrData objectAtIndex:j][@"newsTitle"] length] * K_MAIN_VIEW_SCROLLER_LABLE_WIDTH;    }  }   return left;}  #pragma mark - 新闻点击事件-(void)btnNewsClick:(UIButton *) sender{   NSString *strNewsTitle = sender.titleLabel.text;   UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"系统提示"                          message:strNewsTitle                          delegate:sender                     cancelButtonTitle:@"确定"                     otherButtonTitles:@"其他", nil];  [alert show]; } -(void)scrollerViewClick:(UITapGestureRecognizer*)gesture{   CGPoint touchPoint = [gesture locationInView:scrollViewText];   for (UIButton *btn in scrollViewText.subviews) {     if ([btn.layer.presentationLayer hitTest:touchPoint]) {      [self btnNewsClick:btn];      break;    }   } } @end