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 @interface ViewController : UIViewController{
NSTimer *timer;
UIScrollView *scrollViewText;
}
@property (nonatomic ,strong) NSArray *arrData;
@end

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 offsetX = 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 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