自制简单跑马灯

自编了一个跑马灯，自适应高度和宽度，就一个label显示。

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0,200, 0, 100)];

label.backgroundColor = [UIColor redColor];

label.font = [UIFont systemFontOfSize:15];

label.text = @"书书书书ABC";

CGSize size = [label.text boundingRectWithSize:CGSizeMake(0, label.frame.size.height) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:label.font} context:nil].size;

label.frame = CGRectMake(0, 200, size.width, size.height);

[self.view addSubview:label];

CGRect frame = label.frame;

frame.origin.x = self.view.bounds.size.width;

label.frame = frame;

[UIView beginAnimations:@"testAnimation"context:NULL];

[UIView setAnimationDuration:25];

[UIView setAnimationCurve:UIViewAnimationCurveLinear];

[UIView setAnimationRepeatAutoreverses:NO];

[UIView setAnimationRepeatCount:HUGE_VALF];

frame = label.frame;

frame.origin.x =-label.frame.size.width;

label.frame = frame;

[UIView commitAnimations];