UICollectionView的使用方法及demo

直接上代碼，說明請看註釋吧

ViewController.h

#import <UIKit/UIKit.h> @interface ViewController : UIViewController<UICollectionViewDataSource,UICollectionViewDelegateFlowLayout>{

}
@property (strong, nonatomic)UICollectionView *collectionView;

@end

ViewController.m

#import "ViewController.h" @interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{  [super viewDidLoad];    //肯定是水平滾動，仍是垂直滾動  UICollectionViewFlowLayout *flowLayout=[[UICollectionViewFlowLayout alloc] init];  [flowLayout setScrollDirection:UICollectionViewScrollDirectionVertical];    self.collectionView=[[UICollectionView alloc] initWithFrame:CGRectMake(0, 64, 320, 200) collectionViewLayout:flowLayout];  self.collectionView.dataSource=self;  self.collectionView.delegate=self;  [self.collectionView setBackgroundColor:[UIColor clearColor]];    //註冊Cell，必需要有  [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"UICollectionViewCell"];    [self.view addSubview:self.collectionView];
} #pragma mark -- UICollectionViewDataSource //定義展現的UICollectionViewCell的個數 -(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{  return 10;
} //定義展現的Section的個數 -(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{  return 2;
} //每一個UICollectionView展現的內容 -(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{  static NSString * CellIdentifier = @"UICollectionViewCell";  UICollectionViewCell * cell = [collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];    cell.backgroundColor = [UIColor colorWithRed:((10 * indexPath.row) / 255.0) green:((20 * indexPath.row)/255.0) blue:((30 * indexPath.row)/255.0) alpha:1.0f];  UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];  label.textColor = [UIColor redColor];  label.text = [NSString stringWithFormat:@"%d",indexPath.row];  for (id subView in cell.contentView.subviews) {   [subView removeFromSuperview];  }  [cell.contentView addSubview:label];  return cell;
} #pragma mark --UICollectionViewDelegateFlowLayout //定義每一個Item 的大小 - (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{  return CGSizeMake(60, 60);
} //定義每一個UICollectionView 的 margin -(UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{  return UIEdgeInsetsMake(5, 5, 5, 5);
} #pragma mark --UICollectionViewDelegate //UICollectionView被選中時調用的方法 -(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{  UICollectionViewCell * cell = (UICollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];  //臨時改變個顏色，看好，只是臨時改變的。若是要永久改變，能夠先改數據源，而後在cellForItemAtIndexPath中控制。（和UITableView差很少吧！O(∩_∩)O~）  cell.backgroundColor = [UIColor greenColor];  NSLog(@"item======%d",indexPath.item);  NSLog(@"row=======%d",indexPath.row);  NSLog(@"section===%d",indexPath.section);
} //返回這個UICollectionView是否能夠被選擇 -(BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath
{  return YES;
}

@end