用UILabel实现文字滚动播放（跑马灯）效果

- (void)viewDidLoad {
[super viewDidLoad];//数据源
self.messageArray = [NSArray arrayWithObjects:
@"",
@"",
@"",
nil];
self.msgCount = ;//从第一条开始显示
}

-(void)viewDidAppear:(BOOL)animated {
//播放第一条并加入Timer设定切换间隔时间
[self msgChange];
[NSTimer scheduledTimerWithTimeInterval:5.0f target:self selector:@selector(msgChange) userInfo:nil repeats:YES];
}

- (void)msgChange { if (self.msgCount < self.messageArray.count) {
self.scrollLabel.text = [self.messageArray objectAtIndex:self.msgCount];
self.msgCount++;
} else {
self.scrollLabel.text = @"no message";//此处删除可以改为循环滚动播放
} [self.scrollLabel sizeToFit];
CGRect frame = self.scrollLabel.frame;
frame.origin.x = [UIScreen mainScreen].bounds.size.width;
self.scrollLabel.frame = frame; [UIView beginAnimations:@"scrollLabelTest" context:NULL];
[UIView setAnimationDuration:5.0f];
[UIView setAnimationCurve:UIViewAnimationCurveLinear];
[UIView setAnimationDelegate:self];
[UIView setAnimationRepeatAutoreverses:NO];
[UIView setAnimationRepeatCount:]; frame = self.scrollLabel.frame;
frame.origin.x = -frame.size.width;
self.scrollLabel.frame = frame;
[UIView commitAnimations];
}