基本框架

#pragma mark - UICollectionViewDataSource  
// 指定Section個數  
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {  
  return 3;  
}  
  
// 指定section中的collectionViewCell的個數  
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {  
  return 10;  
}  
  
// 配置section中的collectionViewCell的顯示  
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {  
  CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"CellIdentifier" forIndexPath:indexPath];  
  cell.backgroundColor = [UIColor redColor];  
  cell.textLabel.text = [NSString stringWithFormat:@"(%ld %ld)", indexPath.section, indexPath.row];  
    
  return cell;  
}  

尺寸布局

#pragma mark - UICollectionViewDelegateFlowLayout  
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {  
  return CGSizeMake(self.view.frame.size.width / 3 - 10, self.view.frame.size.width / 3 - 10);  
}  
  
// 設置每個cell上下左右相距  
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {  
  return UIEdgeInsetsMake(5, 5, 5, 5);  
}  
  
// 設置最小行間距，也就是前一行與后一行的中間最小間隔  
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {  
  return 10;  
}  
  
// 設置最小列間距，也就是左行與右一行的中間最小間隔  
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {  
  return 10;  
}  
  
// 設置section頭視圖的參考大小，與tableheaderview類似  
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {  
  return CGSizeMake(self.view.frame.size.width, 40);  
}  
  
// 設置section尾視圖的參考大小，與tablefooterview類似  
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section {  
  return CGSizeMake(self.view.frame.size.width, 40);  
}  

代理方法

#pragma mark - UICollectionViewDelegate  
// 允許選中時，高亮  
- (BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
  return YES;  
}  
  
// 高亮完成后回調  
- (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}  
  
// 由高亮轉成非高亮完成時的回調  
- (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}  
  
// 設置是否允許選中  
- (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
  return YES;  
}  
  
// 設置是否允許取消選中  
- (BOOL)collectionView:(UICollectionView *)collectionView shouldDeselectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
  return YES;  
}  
  
// 選中操作  
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}  
  
// 取消選中操作  
- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}