IOS实现文字水平无间断滚动

IOS实现文字水平无间断滚动

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController{
    NSTimer           *timer;
    UIScrollView      *scrollViewText;
}

@property (nonatomic ,strong) NSArray *arrData;

@end

ViewController.m

//
//  ViewController.m
//  滚动
//
#import "ViewController.h"

#pragma mark - Class define variable
#define K_MAIN_VIEW_SCROLL_HEIGHT 80.0f
#define K_MAIN_VIEW_SCROLL_TEXT_TAG 300
#define K_MAIN_VIEW_TEME_INTERVAL 0.35                //计时器间隔时间(单位秒)
#define K_MAIN_VIEW_SCROLLER_SPACE 20.0f              //每次移动的距离
#define K_MAIN_VIEW_SCROLLER_LABLE_WIDTH     18.0f    //单个字符宽度(与你设置的字体大小一致)
#define K_MAIN_VIEW_SCROLLER_LABLE_MARGIN    20.0f    //前后间隔距离
#define K_MAIN_VIEW_SCROLLER_SLEEP_INTERVAL  1        //停留时间

@interface ViewController ()

@end

@implementation ViewController

#pragma mark - Class property
@synthesize arrData;

- (void)viewDidLoad {
    [super viewDidLoad];

    [self initView];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Custom method
//初始化数据
-(void) initView{

    if (!self.arrData) {
        self.arrData = @[
                          @{
                              @"newsId"   :@"201507070942261935",
                              @"newsImg"  :@"http://bg.fx678.com/HTMgr/upload/UpFiles/20150707/sy_2015070709395519.jpg",
                              @"newsTitle":@"三大理由欧元任性抗跌，欧元区峰会将为希腊定调"
                          },
                          @{
                              @"newsId"    :@"201507070929021220",
                              @"newsImg"   :@"http://bg.fx678.com/HTMgr/upload/UpFiles/20150707/sy_2015070709273545.jpg",
                              @"newsTitle" :@"欧盟峰会或现希腊转机，黄金打响1162保卫战"
                          },
                          @{
                              @"newsId"    :@"201507070656471857",
                              @"newsImg"   :@"http://bg.fx678.com/HTMgr/upload/UpFiles/20150707/2015070706533134.jpg",
                              @"newsTitle" :@"希腊困局欧元不怕，油价服软暴跌8%"
                          }
                      ];
    }

    //文字滚动
    [self initScrollText];

    //开启滚动
    [self startScroll];

}

//文字滚动初始化
-(void) initScrollText{

    //获取滚动条
    scrollViewText = (UIScrollView *)[self.view viewWithTag:K_MAIN_VIEW_SCROLL_TEXT_TAG];
    if(!scrollViewText){
        scrollViewText = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 80, self.view.frame.size.width, K_MAIN_VIEW_SCROLL_HEIGHT)];
        scrollViewText.showsHorizontalScrollIndicator = NO;   //隐藏水平滚动条
        scrollViewText.showsVerticalScrollIndicator = NO;     //隐藏垂直滚动条
        scrollViewText.scrollEnabled = NO;                    //禁用手动滑动

        //横竖屏自适应
        scrollViewText.autoresizingMask = UIViewAutoresizingFlexibleWidth;
        scrollViewText.tag = K_MAIN_VIEW_SCROLL_TEXT_TAG;
        [scrollViewText setBackgroundColor:[UIColor grayColor]];

        //给滚动视图添加事件
        UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollerViewClick:)];
        [scrollViewText addGestureRecognizer:tapGesture];

        //添加到当前视图
        [self.view addSubview:scrollViewText];
    }else{
        //清除子控件
        for (UIView *view in [scrollViewText subviews]) {
            [view removeFromSuperview];
        }
    }

    if (self.arrData) {

        CGFloat offsetX = 0 ,i = 0, h = 30;

        //设置滚动文字
        UIButton *btnText = nil;
        NSString *strTitle = [[NSString alloc] init];

        for (NSDictionary *dicTemp in self.arrData) {

            strTitle = dicTemp[@"newsTitle"];

            btnText = [UIButton buttonWithType:UIButtonTypeCustom];
            [btnText setFrame:CGRectMake([self getTitleLeft:i],
                                         (K_MAIN_VIEW_SCROLL_HEIGHT - h) / 2,
                                         strTitle.length * K_MAIN_VIEW_SCROLLER_LABLE_WIDTH,
                                         h)];

            [btnText setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
            [btnText setTitle:strTitle forState:UIControlStateNormal];

            //横竖屏自适应
            btnText.autoresizingMask = UIViewAutoresizingFlexibleWidth;
            offsetX += btnText.frame.origin.x;

            //设置为 NO,否则无法响应点击事件
            btnText.userInteractionEnabled = NO;

            //添加到滚动视图
            [scrollViewText addSubview:btnText];

            i++;
        }

        //设置滚动区域大小
        [scrollViewText setContentSize:CGSizeMake(offsetX, 0)];
    }
}

#pragma mark - 滚动处理
//开始滚动
-(void) startScroll{

    if (!timer)
        timer = [NSTimer scheduledTimerWithTimeInterval:K_MAIN_VIEW_TEME_INTERVAL target:self selector:@selector(setScrollText) userInfo:nil repeats:YES];

    [timer fire];

}

//滚动处理
-(void) setScrollText{

    [UIView animateWithDuration:K_MAIN_VIEW_TEME_INTERVAL * 2 animations:^{
        CGRect rect;
        CGFloat offsetX = 0.0,width = 0.0;

        for (UIButton *btnText in scrollViewText.subviews) {

            rect = btnText.frame;
            offsetX = rect.origin.x - K_MAIN_VIEW_SCROLLER_SPACE;
            width = [btnText.titleLabel.text length] * K_MAIN_VIEW_SCROLLER_LABLE_WIDTH;

            btnText.frame = CGRectMake(offsetX, rect.origin.y, rect.size.width, rect.size.height);

            NSLog(@"offsetX:%f",offsetX);
        }

        if (offsetX < -width){
            [UIView setAnimationsEnabled:NO];
            [self initScrollText];
        }else
            [UIView setAnimationsEnabled:YES];
    }];

}

#pragma mark - 动态获取左边位置
-(float) getTitleLeft:(CGFloat) i {
    float left = i * K_MAIN_VIEW_SCROLLER_LABLE_MARGIN;

    if (i > 0) {
        for (int j = 0; j < i; j ++) {
            left += [[self.arrData objectAtIndex:j][@"newsTitle"] length] * K_MAIN_VIEW_SCROLLER_LABLE_WIDTH;
        }
    }

    return left;
}

#pragma mark - 新闻点击事件
-(void)btnNewsClick:(UIButton *) sender{

    NSString *strNewsTitle = sender.titleLabel.text;

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"系统提示"
                                                    message:strNewsTitle
                                                   delegate:sender
                                          cancelButtonTitle:@"确定"
                                          otherButtonTitles:@"其他", nil];
    [alert show];

}

-(void)scrollerViewClick:(UITapGestureRecognizer*)gesture{

    CGPoint touchPoint = [gesture locationInView:scrollViewText];

    for (UIButton *btn in scrollViewText.subviews) {

        if ([btn.layer.presentationLayer hitTest:touchPoint]) {
            [self btnNewsClick:btn];
            break;
        }

    }

}

@end

示例源码下载：