Horizontal zentriert UICollectionView Zellen mit benutzerdefinierten Paging

Question

Ich baue derzeit eine App, die einen Twitter-Feed in Form einer horizontalen Sammlung anzeigen muss.

3 Tweets (Zellen) sollten immer sichtbar auf dem Bildschirm und zentriert horizontal sowie einen halben Tweet (letztes Element der vorherigen 3 und erstes Element der nächsten 3) auf beiden Seiten sein.

Here is a picture so it's easier to understand

Wenn der Benutzer blättert es 3 mal 3 bewegen soll (oder weniger, wenn es weniger actualy Zelle ist links zu bewegen). Art eines benutzerdefinierten Paging.

Ich versuchte mit einem Custom layout und es funktioniert und machen die Zellen zentriert, zeigt die Hälfte Tweets auf beiden Seiten genau wie ich will. Aber ich kann es nicht mit dem Scrollen machen, das ich will (3by3). Und es läßt mich nicht die erste oder letzte Zelle vollständig zeigen ... Wie auch immer, wenn ich den folgenden Code habe, es ist nur das benutzerdefinierte Layout Verhalten kündigen, aber blättert 3 von 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]; 
} 

So Leute, hat jemand schon einmal damit gespielt und konnte mir helfen, Dinge zu erledigen? Vielen Dank.

Answer 1

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 

In oben Codierung Ich habe 7 images.So Sie benötigen, um Ihre Bilder über 7 oder less.It Ihr Wunsch haben.

Dann 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{ 
     } 
     } 
    } 
} 

Scroll Delegatmethode

- (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