iOS-tableview顶部拉伸效果(头像拉伸)

例如探探个人信息界面拉伸效果,下拉头像放大

//
// PersonController.m
// Spread
//
// Created by qiuxuewei on 16/3/21.
// Copyright © 2016年 邱学伟. All rights reserved.
//

#import "PersonController.h"

@interface PersonController ()<UITableViewDataSource, UITableViewDelegate, UIScrollViewDelegate>{

}

//属性列表
/** 顶部图片视图 */
@property (nonatomic, strong) UIImageView *headerImageView;
@property (nonatomic, strong) UIView *headerBackView;
/** 个人信息界面 */
@property (nonatomic, strong) UITableView *tableView;

@end

@implementation PersonController
#pragma mark - 懒加载
-(UIView *)headerBackView{
    if (_headerBackView == nil) {
        _headerBackView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, kScreenWidth, 200)];
        [_headerBackView setBackgroundColor:[UIColor lightGrayColor]];
    }
    return _headerBackView;
}
-(UIImageView *)headerImageView{
    if (_headerImageView == nil) {
        _headerImageView = [[UIImageView alloc] init];
        [_headerImageView setImage:[UIImage imageNamed:@"邱_生活.JPG"]];
        [_headerImageView setBackgroundColor:[UIColor greenColor]];
        [_headerImageView setContentMode:UIViewContentModeScaleAspectFill];
        [_headerImageView setClipsToBounds:YES];
    }
    return _headerImageView;
}
-(UITableView *)tableView{
    if (_tableView == nil) {
        _tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, kScreenWidth, kScreenHeight) style:UITableViewStyleGrouped];
        [_tableView setDataSource:self];
        [_tableView setDelegate:self];
    }
    return _tableView;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    //添加子视图
    [self addChildViews];
}
#pragma mark - 类内方法
//添加子视图
-(void)addChildViews{
    //添加表格
    [self.view addSubview:self.tableView];
    //添加头像图片
    [self addHeaderImageView];
}
//添加头像
-(void)addHeaderImageView{
    [self.tableView setTableHeaderView:self.headerBackView];
    [self.headerImageView setFrame:self.headerBackView.bounds];
    [self.headerBackView addSubview:self.headerImageView];
}


#pragma mark - UITableViewDataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return 4;
}

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return 2;
}

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
    return 64;
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
    // 不加此句时，在二级栏目点击返回时，此行会由选中状态慢慢变成非选中状态。
    // 加上此句，返回时直接就是非选中状态。
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
}

//初始化cell
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *ID = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:ID];
    }
    //初始化cell数据!
    [cell.textLabel setText:@"阿伟"];
    [cell.detailTextLabel setText:@"2016-03-22"];

    return cell;
}

//滚动tableview 完毕之后
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{

    //图片高度
    CGFloat imageHeight = self.headerBackView.frame.size.height;
    //图片宽度
    CGFloat imageWidth = kScreenWidth;
    //图片上下偏移量
    CGFloat imageOffsetY = scrollView.contentOffset.y;

    NSLog(@"图片上下偏移量 imageOffsetY:%f ->",imageOffsetY);



    //上移
    if (imageOffsetY < 0) {
        CGFloat totalOffset = imageHeight + ABS(imageOffsetY);
        CGFloat f = totalOffset / imageHeight;

        self.headerImageView.frame = CGRectMake(-(imageWidth * f - imageWidth) * 0.5, imageOffsetY, imageWidth * f, totalOffset);
    }

// //下移
// if (imageOffsetY > 0) {
// CGFloat totalOffset = imageHeight - ABS(imageOffsetY);
// CGFloat f = totalOffset / imageHeight;
// 
// [self.headerImageView setFrame:CGRectMake(-(imageWidth * f - imageWidth) * 0.5, imageOffsetY, imageWidth * f, totalOffset)];
// }


}


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

/* #pragma mark - Navigation // In a storyboard-based application, you will often want to do a little preparation before navigation - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { // Get the new view controller using [segue destinationViewController]. // Pass the selected object to the new view controller. } */

@end