ios 实现类似比微信还好的下拉tableview上面的图片变大的效果

核心代码两个方法：

- (void)viewDidLoad

{

    [superviewDidLoad];

    self.myDataArray = [NSMutableArrayarrayWithObjects:@"小明",@"刘德华",@"李连杰",@"孙俪",@"刘小光",@"小沈阳", nil];

    

    self.tableView = [[UITableViewalloc]initWithFrame:CGRectMake(0, 0, 320, 568)];

    self.tableView.delegate = self;

    self.tableView.dataSource = self;

    self.tableView.backgroundColor = [UIColorlightGrayColor];

    self.tableView.contentInset = UIEdgeInsetsMake(kImageOriginHight, 0, 0, 0);

    [self.view addSubview:self.tableView];

    self.expandZoomImageView = [[UIImageViewalloc]initWithImage:[UIImageimageNamed:@"aaa"]];

    self.expandZoomImageView.frame = CGRectMake(0, -kImageOriginHight - kTempHeight, self.tableView.frame.size.width, kImageOriginHight + kTempHeight);

    

    [self.tableViewaddSubview:self.expandZoomImageView];

}

 

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{

    CGFloat yOffset  = scrollView.contentOffset.y;

    NSLog(@"yOffset===%f",yOffset);

    CGFloat xOffset = (yOffset + kImageOriginHight)/2;

    if (yOffset < -kImageOriginHight) {

        CGRect f = self.expandZoomImageView.frame;

        f.origin.y = yOffset - kTempHeight;

        f.size.height =  -yOffset + kTempHeight;

        f.origin.x = xOffset;

        f.size.width = 320 + fabsf(xOffset)*2;

        self.expandZoomImageView.frame = f;

    }

 

}

 

 

下面是全部的代码。。。。。。。。。

 

 

 

 

//

//  HomeViewController.h

//  expandZoom

//

//  Created by Buddy on 14/7/14.

//  Copyright (c) 2014年 Kyle Fang. All rights reserved.

//

 

#import <UIKit/UIKit.h>

 

@interface HomeViewController : UIViewController<UITableViewDataSource,UITableViewDelegate>

 

@property (nonatomic, strong) UIImageView *expandZoomImageView;

 

@property (nonatomic, strong) UITableView *tableView;

@property (nonatomic, strong) NSMutableArray *myDataArray;

 

 

@end

 

 

//

//  HomeViewController.m

//  expandZoom

//

//  Created by Buddy on 14/7/14.

//  Copyright (c) 2014年 Kyle Fang. All rights reserved.

//

 

#import "HomeViewController.h"

 

static CGFloat kImageOriginHight = 200;

static CGFloat kTempHeight = 80.0f;

@interfaceHomeViewController ()

 

@end

 

@implementation HomeViewController

 

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

{

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self) {

        // Custom initialization

    }

    returnself;

}

 

- (void)viewDidLoad

{

    [superviewDidLoad];

    self.myDataArray = [NSMutableArrayarrayWithObjects:@"小明",@"刘德华",@"李连杰",@"孙俪",@"刘小光",@"小沈阳", nil];

    

    self.tableView = [[UITableViewalloc]initWithFrame:CGRectMake(0, 0, 320, 568)];

    self.tableView.delegate = self;

    self.tableView.dataSource = self;

    self.tableView.backgroundColor = [UIColorlightGrayColor];

    self.tableView.contentInset = UIEdgeInsetsMake(kImageOriginHight, 0, 0, 0);

    [self.view addSubview:self.tableView];

    self.expandZoomImageView = [[UIImageViewalloc]initWithImage:[UIImageimageNamed:@"aaa"]];

    self.expandZoomImageView.frame = CGRectMake(0, -kImageOriginHight - kTempHeight, self.tableView.frame.size.width, kImageOriginHight + kTempHeight);

    

    [self.tableViewaddSubview:self.expandZoomImageView];

}

 

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{

    CGFloat yOffset  = scrollView.contentOffset.y;

    NSLog(@"yOffset===%f",yOffset);

    CGFloat xOffset = (yOffset + kImageOriginHight)/2;

    if (yOffset < -kImageOriginHight) {

        CGRect f = self.expandZoomImageView.frame;

        f.origin.y = yOffset - kTempHeight;

        f.size.height =  -yOffset + kTempHeight;

        f.origin.x = xOffset;

        f.size.width = 320 + fabsf(xOffset)*2;

        self.expandZoomImageView.frame = f;

    }

}

 

 

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{

    return 44;

}

 

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{

    returnself.myDataArray.count;

}

 

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *myCell = @"MyCellIndifer";

    UITableViewCell *cell = [[UITableViewCellalloc]initWithStyle:UITableViewCellStyleDefaultreuseIdentifier:myCell];

    

    cell.textLabel.text = [self.myDataArray objectAtIndex:indexPath.row];

    

    return cell;

}

 

 

 

 

@end