iOS仿网易简单头部滚动效果

//// TitleScrollView.h// @author 陈晋添//// Created by jkc on 16/7/14.// Copyright © 2016年 cjt. All rights reserved.//#import <UIKit/UIKit.h>@interface TitleScrollView : UIScrollViewtypedef void(^sectionTitleViewBlock)(NSInteger num);@property (nonatomic, strong) NSMutableArray *BtnArr;   //形成的按钮数组@property (nonatomic, strong) UILabel *linelabel;    //底部line@property (nonatomic, strong) sectionTitleViewBlock clickBolck; //block回调@property (nonatomic, assign) NSInteger LineWidth;    //设置线的长度@property (nonatomic, assign) NSInteger ButtonWidth;   //按钮的宽度/** * 通过标题数组进行设置头部滚动条 * * @param array 需要加入的标题 */-(void)AddArrView:(NSArray*)array;/** * 可直接用代码设置索引位置 * * @param index 索引位置 */-(void)setByIndex:(NSInteger)index;@end

//// TitleScrollView.m// @author 陈晋添//// Created by jkc on 16/7/14.// Copyright © 2016年 cjt. All rights reserved.//#import "TitleScrollView.h"#define TitleBtnTag 300   //button的tag值@implementation TitleScrollView-(instancetype)initWithFrame:(CGRect)frame{ if (self = [super initWithFrame:frame]) {  //初始化自身  [self setBackgroundColor:[UIColor whiteColor]];  self.showsHorizontalScrollIndicator = false;  _ButtonWidth = _LineWidth = 60;  self.linelabel = [[UILabel alloc] initWithFrame:CGRectMake(0, self.frame.size.height-1.5, _LineWidth, 1.5)];  [self.linelabel setBackgroundColor:TintColor];  [self addSubview:self.linelabel]; } return self;}-(void)AddArrView:(NSArray*)array{ self.BtnArr = [NSMutableArray array]; for (int i=0; i<array.count; i++) {  //初始化所有btn  UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(i*_ButtonWidth, 0, _ButtonWidth,34)];  [btn addTarget:self action:@selector(click:) forControlEvents:UIControlEventTouchUpInside];  btn.titleLabel.font = [UIFont systemFontOfSize:12];  btn.titleLabel.textAlignment = NSTextAlignmentCenter;  [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];  [btn setTitle:array[i] forState:UIControlStateNormal];  btn.tag = TitleBtnTag+i;  [self addSubview:btn];  [self.BtnArr addObject:btn]; } //根据button个数设置内部大小 [self setContentSize:CGSizeMake(array.count*_ButtonWidth, CGRectGetHeight(self.frame))];}-(void)click:(UIButton*)button{ //把所有的btn样式重置 for (UIButton *btn in self.BtnArr) {  btn.titleLabel.font = [UIFont systemFontOfSize:12];  btn.titleLabel.textAlignment = NSTextAlignmentCenter;  [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal]; } //特殊设置点击的button样式 [button setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal]; //计算获得偏移量， CGFloat index = (button.tag-TitleBtnTag)*_ButtonWidth-(self.frame.size.width-_ButtonWidth)/2; index = index<0?0:index; index = index>self.contentSize.width-CGRectGetWidth(self.frame)?self.contentSize.width-CGRectGetWidth(self.frame):index; //动画效果偏移 [self setContentOffset:CGPointMake(index, 0) animated:YES]; [UIView animateWithDuration:0.3 animations:^{  self.linelabel.frame = CGRectMake((button.tag-TitleBtnTag)*_ButtonWidth, self.frame.size.height-1, _LineWidth, 1); }]; self.clickBolck(button.tag);}//通过外部代码直接设置索引-(void)setByIndex:(NSInteger)nowindex{ UIButton *button = self.BtnArr[nowindex]; [self click:button];}@end