Question

尝试使用UICollectionView对我的单元格进行居中对齐并启用分页。不幸的是，在尝试这样做时，我永远不会让细胞在中心对齐。当我滚动浏览集合时，单元格总是稍微移开。我试图在纵向和横向视图中实现此目的。我一直在使用插图试图使细胞及其位置居中：

- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    CGFloat cellSpacing = ((UICollectionViewFlowLayout *) collectionViewLayout).minimumLineSpacing;
    CGFloat cellWidth = ((UICollectionViewFlowLayout *) collectionViewLayout).itemSize.width;
    NSInteger cellCount = [collectionView numberOfItemsInSection:section];
    CGFloat inset = (collectionView.bounds.size.width - ((cellCount) * (cellWidth + cellSpacing))) * 0.5;
    inset = MAX(inset, 0.0);

    if(UIDeviceOrientationIsPortrait([UIDevice currentDevice].orientation)){
         return UIEdgeInsetsMake(50.0,inset,0.0,inset);  // top, left, bottom, right
     }
     else{
         return UIEdgeInsetsMake(50.0,inset,0.0,inset);  // top, left, bottom, right
     }
}

然后我改变了行间距：

-(CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)
collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section{

    CGFloat cellSpacing = ((UICollectionViewFlowLayout *) collectionViewLayout).minimumLineSpacing;
    CGFloat cellWidth = ((UICollectionViewFlowLayout *) collectionViewLayout).itemSize.width;
    NSInteger cellCount = [collectionView numberOfItemsInSection:section];
    CGFloat inset = (collectionView.bounds.size.width - ((cellCount-1) * (cellWidth + cellSpacing))) * 0.5;
    inset = MAX(inset, 0.0);

    if(UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation)){

        NSLog(@"Changed to landscape Spacing");
        return inset;

    }
    else{

        return inset;
    }

我的细胞大小设置在这里：

-(CGSize)
    collectionView:(UICollectionView *) collectionView
    layout:(UICollectionViewLayout*)collectionViewLayout
    sizeForItemAtIndexPath:(NSIndexPath *)indexPath{

    //Set Landscape size of cells
    if(UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation)){
        CGFloat cellWidth =  [[UIScreen mainScreen] bounds].size.width-360;
        CGFloat cellHeigt = [[UIScreen mainScreen] bounds].size.height-60;
        NSLog(@"Is Landscape");
        return CGSizeMake(cellWidth, cellHeigt);
    }
    //Set Potrait size of cells
    else{
        CGFloat cellWidth =  [[UIScreen mainScreen] bounds].size.width-60;
        CGFloat cellHeigt = [[UIScreen mainScreen] bounds].size.height-160;
        NSLog(@"Is Portrait");
        return CGSizeMake(cellWidth, cellHeigt);
    }
}

Answer 1

您可以简单地将单元格设置为占据UICollectionView的整个宽度，并使用autoLayout将内容置于内部中，而不是尝试以编程方式设置框架，这样您就不必考虑界面更改和不同的屏幕大小，因为autoLayout将为您处理。在您的数据源中，

-(CGSize)
    collectionView:(UICollectionView *) collectionView
    layout:(UICollectionViewLayout*)collectionViewLayout
    sizeForItemAtIndexPath:(NSIndexPath *)indexPath{

    return CGSizeMake(collectionView.bounds.size.width, collectionView.bounds.size.height)
}

将所有项间间距设置为0，并为UICollectionView

启用分页

接下来只需使用autoLayout将内容设置为单元格中心！

Answer 2

试试这个。你必须拿UICollectionViewFlowLayout并设置它的滚动方向，最小空间并附加到集合视图布局。

UICollectionViewFlowLayout *flowLayout;

    - (void)viewDidLoad {
        [super viewDidLoad];
     flowLayout = [[UICollectionViewFlowLayout alloc]init];

        flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
        flowLayout.minimumInteritemSpacing = 0.0;

        flowLayout.minimumLineSpacing = 0.0;

        _obj_CollectionView.pagingEnabled = YES;
        _obj_CollectionView.collectionViewLayout = flowLayout;
    }

如果要垂直滚动修改它。

希望它能奏效。

启用了分页的UICollectionView Center Cells

2 个答案: