跑马灯

- (void)viewDidLoad
{
    [super viewDidLoad];
   
    UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(100, 100, 130, 20)];
    label.text = @"跑马灯开始了！";
    label.tag = 10;
    [self.view addSubview:label];
    
    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.8 target:self selector:@selector(moveString) userInfo:nil repeats:YES];
    [timer fire];
}

-(void)moveString
{
    UILabel *label = (UILabel*)[self.view viewWithTag:10];
    NSString *moveStr = [[NSString alloc]initWithFormat:@"%@%@",[label.text substringWithRange:NSMakeRange(1, label.text.length-1)],[label.text substringWithRange:NSMakeRange(0,1)]];
    label.text = moveStr;
}