Ios 指定UICollectionView的行和列编号

我想显示一个UICollectionView，它正好包含2行，每行包含100个单元格

// 1
- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section {

    return 100;
}
// 2
- (NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionView {
    return 2;
}
// 3
- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    MyCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];

        cell.lbl.text = @"Data";

    return cell;
}

我明白了：

如何为UICollectionView指定行号？我想创建一个2x100表。

试试以下方法：

// 1
- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section {

    return 2;
}
// 2
- (NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionView {
    return 100;
}
// 3
- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    MyCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];

        cell.lbl.text = @"Data";

    return cell;
}

---

假设单元格大小允许，则节数决定每行中有多少单元格

---

节将始终以新行开始

每行3个单元格。。添加此代码

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
     return CGSizeMake(collectionView.frame.size.width/3.2 , 100);
}

---

对于Swift：每列3行（使用@SakhshiSingla Answer）

---

在集合视图中实现n列的更通用方法是

 func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

   // flow layout have all the important info like spacing, inset of collection view cell, fetch it to find out the attributes specified in xib file
   guard let flowLayout = collectionViewLayout as? UICollectionViewFlowLayout else {
        return CGSize()
    }

    // subtract section left/ right insets mentioned in xib view

    let widthAvailbleForAllItems =  (collectionView.frame.width - flowLayout.sectionInset.left - flowLayout.sectionInset.right)

    // Suppose we have to create nColunmns
    // widthForOneItem achieved by sunbtracting item spacing if any

    let widthForOneItem = widthAvailbleForAllItems / nColumns - flowLayout.minimumInteritemSpacing


    // here height is mentioned in xib file or storyboard
    return CGSize(width: CGFloat(widthForOneItem), height: (flowLayout.itemSize.height))
 }

---

此方法需要

UICollectionViewDelegateFlowLayout

协议。是的，我们确实需要。看一看：@SakshiSingla为什么要用3.2？只是计算而已！您可以指定u的计算方式吗？我希望对每行的4个和5个单元格使用相同的计算方式。谢谢你确定没有其他关键步骤可以让这个方法发挥作用吗？函数在这里不调用。

 func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

   // flow layout have all the important info like spacing, inset of collection view cell, fetch it to find out the attributes specified in xib file
   guard let flowLayout = collectionViewLayout as? UICollectionViewFlowLayout else {
        return CGSize()
    }

    // subtract section left/ right insets mentioned in xib view

    let widthAvailbleForAllItems =  (collectionView.frame.width - flowLayout.sectionInset.left - flowLayout.sectionInset.right)

    // Suppose we have to create nColunmns
    // widthForOneItem achieved by sunbtracting item spacing if any

    let widthForOneItem = widthAvailbleForAllItems / nColumns - flowLayout.minimumInteritemSpacing


    // here height is mentioned in xib file or storyboard
    return CGSize(width: CGFloat(widthForOneItem), height: (flowLayout.itemSize.height))
 }