我目前正在构建一个必须以水平集合视图的形式呈现Twitter Feed的应用。
3个推文（单元格）应始终在屏幕上可见，并且水平居中，以及两侧的推文（前3个的最后一个元素和下一个3的第一个元素）。
Here is a picture so it's easier to understand
当用户滚动时，它应该滚动3乘3（或者更小，如果实际上有更少的单元格滚动）。自定义分页的排序。
我尝试使用Custom layout并且它可以正常工作并使细胞居中，就像我想要的那样在两侧显示半条推文。但我无法使用我想要的滚动功能（3by3）。并且它不会让我完全显示第一个或最后一个单元格...无论如何，当我有下面的代码时，它只是取消自定义布局行为，但是滚动3乘3 ...
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
float pageWidth = ((self.view.frame.size.width / 4)*3);
float currentOffset = scrollView.contentOffset.x;
float targetOffset = targetContentOffset->x;
float newTargetOffset = 0;
if (targetOffset > currentOffset)
newTargetOffset = ceilf(currentOffset / pageWidth) * pageWidth;
else
newTargetOffset = floorf(currentOffset / pageWidth) * pageWidth;
if (newTargetOffset < 0)
newTargetOffset = 0;
else if (newTargetOffset > scrollView.contentSize.width)
newTargetOffset = scrollView.contentSize.width;
targetContentOffset->x = currentOffset;
[scrollView setContentOffset:CGPointMake(newTargetOffset, 0) animated:YES];
}
所以，伙计们，之前有没有人玩过这个并且可以帮助我完成任务？非常感谢。
答案 0 :(得分：0)
ViewController.h
#import <UIKit/UIKit.h>
#import "CustomCell.h"
#import "DetailimageViewController.h"
@interface RootViewController : UIViewController<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
{
IBOutlet UICollectionView *collectionViewHorizontalVertical;
}
ViewController.m
#import "RootViewController.h"
@interface RootViewController ()
{
NSMutableArray *arrayImages;
DetailimageViewController *detailImageVC ;
}
@end
@implementation RootViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
arrayImages = [[NSMutableArray alloc]initWithObjects:@"iMove.jpg",@"iPad.jpg",@"iPhone.jpg",@"iPod.jpg",@"iRing.jpg",@"iTV.jpg",@"iwatch.jpeg",nil];
UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;
UINib *cellNib = [UINib nibWithNibName:@"CustomCell" bundle:nil];
[collectionViewHorizontalVertical registerNib:cellNib forCellWithReuseIdentifier:@"cvCell"];
}
//UICollectionView DataSource and Delegate Methods
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return arrayImages.count;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = @"cvCell";
CustomCell *cell = (CustomCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellIdentifier forIndexPath:indexPath];
cell.imgViewCollection.image = [UIImage imageNamed:[arrayImages objectAtIndex:indexPath.row]];
return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(@"The indexPath is - %ld",(long)indexPath.item);
int ind = (int)indexPath.item;
detailImageVC = [[DetailimageViewController alloc]initWithNibName:@"DetailimageViewController" bundle:nil];
detailImageVC.arrayImagesCount = arrayImages;
detailImageVC.intSelectedIndex = ind;
[[NSUserDefaults standardUserDefaults] setObject:[NSString stringWithFormat:@"%d",detailImageVC.intSelectedIndex] forKey:@"SelectedCollectionViewID"];
[[NSUserDefaults standardUserDefaults] synchronize];
[self.navigationController pushViewController:detailImageVC animated:YES];
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
return CGSizeMake(200, 200);
}
@end
在上面的编码中我有7张图像。所以你需要让你的图像在7以上。这是你的愿望。
然后是DetailimageViewController.h
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
@interface DetailimageViewController : UIViewController<UIScrollViewDelegate>
{
}
@property (strong, nonatomic) NSMutableArray *arrayImagesCount;
@property (strong, nonatomic) IBOutlet UIScrollView *scroll;
@property (strong, nonatomic) IBOutlet UIPageControl *pageControl;
@property (strong, nonatomic) IBOutlet UIImageView *imageviewScrollView
@property (assign, nonatomic) NSInteger seletedIndex;
@property (strong, nonatomic) UIImage *imageSelection;
@property (nonatomic, assign) int intSelectedIndex;
@property (nonatomic, strong) NSArray *pageImages;
@property (nonatomic, assign) CGFloat lastContentOffset;
- (IBAction)actionBack:(id)sender;
@end
DetailimageViewController.m
#import "DetailimageViewController.h"
@interface DetailimageViewController ()
{
UIImageView *subimg;
}
@end
@implementation DetailimageViewController
typedef enum ScrollDirection
{
ScrollDirectionNone,
ScrollDirectionRight,
ScrollDirectionLeft,
ScrollDirectionUp,
ScrollDirectionDown,
ScrollDirectionCrazy,
} ScrollDirection;
@synthesize arrayImagesCount;
@synthesize scroll;
@synthesize seletedIndex;
@synthesize imageSelection;
@synthesize intSelectedIndex;
@synthesize pageImages = _pageImages;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
scroll.layer.cornerRadius=8.0f;
scroll.layer.masksToBounds=YES;
scroll.layer.borderColor=[[UIColor redColor]CGColor];
scroll.layer.borderWidth= 1.0f;
NSInteger pageCount = arrayImagesCount.count;
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
int intCollectionViewIndex = [[defaults valueForKey:@"SelectedCollectionViewID"]intValue];
if(intSelectedIndex == intCollectionViewIndex)
{
for (int i=intSelectedIndex; i<[arrayImagesCount count]; i++)
{
CGRect frame;
if(i == intCollectionViewIndex)
{
frame.origin.x = self.scroll.frame.size.width *intCollectionViewIndex;
frame.origin.y=0;
frame.size=self.scroll.frame.size;
subimg=[[UIImageView alloc]initWithFrame:CGRectMake(self.scroll.frame.size.width *intCollectionViewIndex,0,self.scroll.frame.size.width,self.scroll.frame.size.height)];
subimg.image=[UIImage imageNamed:[NSString stringWithFormat:@"%@",[arrayImagesCount objectAtIndex:i]]];
[self.scroll addSubview:subimg];
[self.scroll setContentOffset:CGPointMake(self.scroll.frame.size.width*i,-20) animated:YES];
self.scroll.contentSize = CGSizeMake(self.scroll.frame.size.width*arrayImagesCount.count, self.scroll.frame.size.height);
}
else{
}
}
}
}
ScrollView委派方法
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
NSLog(@" Offset = %@ ",NSStringFromCGPoint(scrollView.contentOffset));
ScrollDirection scrollDirection;
if (self.lastContentOffset > scrollView.contentOffset.x)
{
scrollDirection = ScrollDirectionRight;
NSLog(@"The scrollview is scrolling right side");
for(int j=intSelectedIndex;j<[arrayImagesCount count];j--)
{
CGRect frameRight;
frameRight.origin.x = self.scroll.frame.size.width *j;
frameRight.origin.y=0;
frameRight.size=self.scroll.frame.size;
subimg=[[UIImageView alloc]initWithFrame:CGRectMake(self.scroll.frame.size.width *j,0,self.scroll.frame.size.width,self.scroll.frame.size.height)];
subimg.image=[UIImage imageNamed:[NSString stringWithFormat:@"%@",[arrayImagesCount objectAtIndex:j]]];
[self.scroll addSubview:subimg];
self.scroll.contentSize = CGSizeMake(self.scroll.frame.size.width*arrayImagesCount.count, self.scroll.frame.size.height);
}
}
else if (self.lastContentOffset < scrollView.contentOffset.x)
{
scrollDirection = ScrollDirectionLeft;
NSLog(@"The scrollview is scrolling left side");
for(int k=intSelectedIndex;k<[arrayImagesCount count];k++)
{
CGRect frameLeft;
frameLeft.origin.x = self.scroll.frame.size.width *k;
frameLeft.origin.y=0;
frameLeft.size=self.scroll.frame.size;
subimg=[[UIImageView alloc]initWithFrame:CGRectMake(self.scroll.frame.size.width *k,0,self.scroll.frame.size.width,self.scroll.frame.size.height)];
subimg.image=[UIImage imageNamed:[NSString stringWithFormat:@"%@",[arrayImagesCount objectAtIndex:k]]];
[self.scroll addSubview:subimg];
self.scroll.contentSize = CGSizeMake(self.scroll.frame.size.width*arrayImagesCount.count, self.scroll.frame.size.height);
}
}
self.lastContentOffset = scrollView.contentOffset.x;
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
CGPoint translation = [scrollView.panGestureRecognizer translationInView:scrollView.superview];
NSLog(@"The translation.x is - %f",translation.x);
NSLog(@"The scrollview content off set is - %f",scrollView.contentOffset.x);
if ([scrollView.panGestureRecognizer translationInView:scrollView.superview].x > 0) {
// handle dragging to the right
NSLog(@"It is dragging to right side");
} else {
// handle dragging to the left
NSLog(@"It is dragging to left side");
}
}
- (IBAction)actionBack:(id)sender
{
[self.navigationController popViewControllerAnimated:YES];
}
@end