我如何在UICollectionView的一个部分设置单元格间距?我知道有一个属性minimumInteritemSpacing，我已经将它设置为5.0，但间距仍然没有出现5.0。我已经实现了flowout委托方法。
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
return 5.0;
}
我仍然没有得到想要的结果。我认为这是最小间距。有没有什么方法可以设置最大间距?
当前回答
支持第一个问题。我试图在UICollectionView上获得5px的间距，但这并不奏效，以及UIEdgeInsetsMake(0,0,0,0)…
在UITableView中，我可以通过直接指定一行中的x,y坐标来做到这一点。
这是我的UICollectionView代码:
#pragma mark collection view cell layout / size
- (CGSize)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return [self getCellSize:indexPath]; // will be w120xh100 or w190x100
// if the width is higher, only one image will be shown in a line
}
#pragma mark collection view cell paddings
- (UIEdgeInsets)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, 0, 0, 0); // top, left, bottom, right
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 5.0;
}
更新:用下面的代码解决了我的问题。
ViewController。m
#import "ViewController.h"
#import "MagazineCell.h" // created just the default class.
static NSString * const cellID = @"cellID";
@interface ViewController ()
@end
@implementation ViewController
#pragma mark - Collection view
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 30;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MagazineCell *mCell = (MagazineCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
mCell.backgroundColor = [UIColor lightGrayColor];
return mCell;
}
#pragma mark Collection view layout things
// Layout: Set cell size
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"SETTING SIZE FOR ITEM AT INDEX %d", indexPath.row);
CGSize mElementSize = CGSizeMake(104, 104);
return mElementSize;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
// Layout: Set Edges
- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
// return UIEdgeInsetsMake(0,8,0,8); // top, left, bottom, right
return UIEdgeInsetsMake(0,0,0,0); // top, left, bottom, right
}
@end
其他回答
我有问题与接受的答案，所以我更新了它，这是为我工作:
.h
@interface MaxSpacingCollectionViewFlowLayout : UICollectionViewFlowLayout
@property (nonatomic,assign) CGFloat maxCellSpacing;
@end
.m
@implementation MaxSpacingCollectionViewFlowLayout
- (NSArray *) layoutAttributesForElementsInRect:(CGRect)rect {
NSArray *attributes = [super layoutAttributesForElementsInRect:rect];
if (attributes.count <= 0) return attributes;
CGFloat firstCellOriginX = ((UICollectionViewLayoutAttributes *)attributes[0]).frame.origin.x;
for(int i = 1; i < attributes.count; i++) {
UICollectionViewLayoutAttributes *currentLayoutAttributes = attributes[i];
if (currentLayoutAttributes.frame.origin.x == firstCellOriginX) { // The first cell of a new row
continue;
}
UICollectionViewLayoutAttributes *prevLayoutAttributes = attributes[i - 1];
CGFloat prevOriginMaxX = CGRectGetMaxX(prevLayoutAttributes.frame);
if ((currentLayoutAttributes.frame.origin.x - prevOriginMaxX) > self.maxCellSpacing) {
CGRect frame = currentLayoutAttributes.frame;
frame.origin.x = prevOriginMaxX + self.maxCellSpacing;
currentLayoutAttributes.frame = frame;
}
}
return attributes;
}
@end
在头文件中定义UICollectionViewDelegateFlowLayout协议。
实现UICollectionViewDelegateFlowLayout协议的如下方法:
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
return UIEdgeInsetsMake(5, 5, 5, 5);
}
点击这里查看苹果文档的UIEdgeInsetMake方法。
使用水平流布局，我也得到了10点之间的单元格间距。为了移除间距，我需要将minimumlinespespaces和minimumInterItemSpacing设置为零。
UICollectionViewFlowLayout *flow = [[UICollectionViewFlowLayout alloc] init];
flow.itemSize = CGSizeMake(cellWidth, cellHeight);
flow.scrollDirection = UICollectionViewScrollDirectionHorizontal;
flow.minimumInteritemSpacing = 0;
flow.minimumLineSpacing = 0;
此外，如果所有单元格大小相同，直接在流布局上设置属性比使用委托方法更简单、更有效。
支持第一个问题。我试图在UICollectionView上获得5px的间距，但这并不奏效，以及UIEdgeInsetsMake(0,0,0,0)…
在UITableView中，我可以通过直接指定一行中的x,y坐标来做到这一点。
这是我的UICollectionView代码:
#pragma mark collection view cell layout / size
- (CGSize)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return [self getCellSize:indexPath]; // will be w120xh100 or w190x100
// if the width is higher, only one image will be shown in a line
}
#pragma mark collection view cell paddings
- (UIEdgeInsets)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, 0, 0, 0); // top, left, bottom, right
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 5.0;
}
更新:用下面的代码解决了我的问题。
ViewController。m
#import "ViewController.h"
#import "MagazineCell.h" // created just the default class.
static NSString * const cellID = @"cellID";
@interface ViewController ()
@end
@implementation ViewController
#pragma mark - Collection view
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 30;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MagazineCell *mCell = (MagazineCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
mCell.backgroundColor = [UIColor lightGrayColor];
return mCell;
}
#pragma mark Collection view layout things
// Layout: Set cell size
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"SETTING SIZE FOR ITEM AT INDEX %d", indexPath.row);
CGSize mElementSize = CGSizeMake(104, 104);
return mElementSize;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
// Layout: Set Edges
- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
// return UIEdgeInsetsMake(0,8,0,8); // top, left, bottom, right
return UIEdgeInsetsMake(0,0,0,0); // top, left, bottom, right
}
@end
我使用monotouch，所以名称和代码会有点不同，但你可以通过确保集合视图的宽度等于(x *单元格宽度)+ (x-1) * MinimumSpacing与x =每行单元格的数量来做到这一点。
只需要根据MinimumInteritemSpacing和Cell的宽度执行以下步骤
1)我们根据单元格大小+当前插入+最小间距计算每行项目的数量
float currentTotalWidth = CollectionView.Frame.Width - Layout.SectionInset.Left - Layout.SectionInset.Right (Layout = flowlayout)
int amountOfCellsPerRow = (currentTotalWidth + MinimumSpacing) / (cell width + MinimumSpacing)
2)现在你有了所有信息来计算集合视图的预期宽度
float totalWidth =(amountOfCellsPerRow * cell width) + (amountOfCellsPerRow-1) * MinimumSpacing
3)所以当前宽度与预期宽度之差为
float difference = currentTotalWidth - totalWidth;
4)现在调整insets(在本例中，我们将其添加到右侧，因此集合视图的左侧位置保持不变
Layout.SectionInset.Right = Layout.SectionInset.Right + difference;
