李大仁博客

跑马灯效果的滚动条，一般出现在 ios 应用的底部。用于显示动态变化的信息或内容较长的信息，在个类应用中使用广泛 以下两种可用的跑马灯滚动 MarqueeBar 的实现。

1. 直接在 ViewController 中实现对 UIView 的位置定时移动来实现，以下代码直接加入到 ViewController 中，在 viewWillAppear 中调用 loadView 即可。

- (void)marqueeView
{

CGRect frame = self.vMarqueeContainer.frame;
frame.origin.x = frame.origin.x -2;
if(frame.origin.x < -frame.size.width )
{
    frame.origin.x  = 320;
}
self.vMarqueeContainer.frame = frame;

//延时递归调用
\[self performSelector:@selector(marqueeView) withObject:nil afterDelay:0.04\];

}

• (void)loadView
  {
  //marqueenbar 背景，位置高度等控制
  UIView *viewMarqueeBar = [[[UIView alloc]initWithFrame(0, 347, 320, 20)]autorelease];
  [viewMarqueeBar setBackgroundColor:[UIColor darkGrayColor]];

  // 滚动容器，显示滚动范围
  UIView *viewMarqueeContainer = [[[UIView alloc]initWithFrame(320, 3, 360, 14)]autorelease];
  [viewMarqueeContainer setBackgroundColor:[UIColor clearColor]];
  [viewMarqueeContainer setClipsToBounds];
  [viewMarqueeContainer setOpaque];

  // 内容
  UILabel *lblContent = [[[UILabel alloc] initWithFrame(0, 0, 50,14)]autorelease];
  [lblContent setText:@"这里是滚动条。。。。。"];
  [lblContent setTextColor:[UIColor whiteColor]];
  [lblContent setBackgroundColor:[UIColor clearColor]];
  [lblContent setFont:[UIFont fontWithName:@"Helvetica" size:12]];
  [lblContent setOpaque];

  self.view= viewMarqueeBar;
  self.vMarqueeContainer = viewMarqueeContainer;

  [self.view addSubview];

  [self marqueeView];
  }

2. 自行定义滚动条控件，让 view 自己滚动起来，通过不断的相互方法调用实现循环滚动 UIMarqueeBarView.h 定义

/**
*UIMarqueeBarView.h
*/
@interface UIMarqueeBarView : UIView
{
}

• (void)start;
• (void)stop;
  @end

UIMarqueeBarView.m 实现

/**
*UIMarqueeBarView.m
*/

#import "UIMarqueeBarView.h"

@implementation UIMarqueeBarView

• (void)dealloc
  {
  [super dealloc];
  }

• (id)initWithFrame:(CGRect)frame
  {
  self = [super initWithFrame];
  if (self) {
  // Initialization code
  [self setupView];
  }
  return self;
  }

-(id)initWithCoder:(NSCoder *)aDecoder {
if( (self = [super initWithCoder]) ) {
// Initialization code
[self setupView];
}
return self;
}

• (void)setupView
  {
  [self setBackgroundColor:[UIColor lightGrayColor]];
  [self setClipsToBounds];
  [self setOpaque];

  UILabel *lblContent = [[[UILabel alloc] initWithFrame(0, 0, 150 ,16)]autorelease];
  [lblContent setText:@"这里是滚动条。。。。。"];
  [lblContent setTextColor:[UIColor whiteColor]];
  [lblContent setBackgroundColor:[UIColor clearColor]];
  [lblContent setFont:[UIFont fontWithName:@"Helvetica" size:14]];
  [lblContent setNumberOfLines:1];
  [lblContent setOpaque];

  [self addSubview];
  }

• (void)start
  {
  if (self.viewContainer == NULL) {
  [self setupView];
  }

  [self startAnimation];
  }

• (void)stop
  {

}

-(void)startAnimation
{
[UIView beginAnimations:@"MarqueeBarAniamation" context];
[UIView setAnimationCurve];
[UIView setAnimationDuration:25];
[UIView setAnimationDelegate];
[UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];

CGRect viewFrame = self.viewContainer.frame;
viewFrame.origin.x = -320;
\[self.viewContainer setFrame:viewFrame\];

\[UIView commitAnimations\];

}

-(void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
{
CGRect viewFrame = self.viewContainer.frame;
viewFrame.origin.x = 320;
[self.viewContainer setFrame];
[self startAnimation];
}