YFRollingLabel is a rolling Label using NSTimer.
博客园记录: 【IOS】自定义可点击的多文本跑马灯YFRollingLabel
##Effection:
if only one text need to be shown it will roll in a fixed direction automatic.

if more than one text need to be shown it will roll circularly.

if the width of the only one text is smaller than view's width
it won't roll.
Please notice that Only Two Labels are used in this "YFRollingLabel".
so if you set the "InternalWidth" and text a short width, it will break into showing the next label suddenly instead of smothly;
####1.import "YFRollingLabel.h"
####2.Initialization:
YFRollingLabel *label = [[YFRollingLabel alloc] initWithFrame:frame textArray:@[@The first One”,@“The Second One”,@“The Third One”,@“The Last One”] font:[UIFont systemFontOfSize:20] textColor:[UIColor whiteColor]];
####3.Property:
speed: pixel rolling for every 0.02s, default : 1.0f. internalWidth: the width between two labels, default : a third of view's width. orientation: rolling from left to right or not: default : RollingOrientationLeft.
####4.Method about Timer:
-(void)beginTimer; start rolling. -(void)pauseTimer; pause rolling. -(void)stopTimer; stop rolling.
####5.ClickEventBlock:
label.labelClickBlock = ^(NSInteger index){ //Your Code. };