一、集合视图的概念
1、如何创建UIColletionView
2、集合视图的布局UICollectionViewFlowLayyout
3、自定义cell
4、布局协议UICollectionViewDelegateFlowLayout
5、UICollectonView与UITableView的实现类似，都需要设置delegate和dataSource
6、在collectionView中,cell的布局比tableView要复杂，需要使用一个类来描述集合视图的布局---UICollectionViewLayout->UICollectionViewFlowLayout
二、创建步骤
1.使用系统布局UICollectionViewFlowLayout
2.创建UICollectionView
3.设置代理，设置数据源
4.设置自定义Cell
数据源
我们需要给collectionView指定一个数据源，它负责给对collectionView提供数据与显示
#import"JYFViewController.h"
#import"Model.h"
#import"MyCell.h"
#import"MyHeader.h"
#import"MyFooter.h"
#import"UIImageView+WebCache.h"
@interfaceJYFViewController()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
@property(nonatomic,retain)NSMutableArray*allDataArray;
@end
@implementationJYFViewController
- (void)viewDidLoad
{
[superviewDidLoad];
// 1.获取文件路径
NSString*filePath = [[NSBundlemainBundle]pathForResource:@"Data"ofType:@"json"];
// 2.读取文件数据
NSData*data = [NSDatadataWithContentsOfFile:filePath];
// 3.解析数据
NSArray*array = [NSJSONSerializationJSONObjectWithData:dataoptions:NSJSONReadingAllowFragments error:nil];
// 4.遍历放入大数组中
self.allDataArray= [NSMutableArrayarray];
for(NSDictionary*dictinarray) {
Model*model = [Modelnew];
[modelsetValuesForKeysWithDictionary:dict];
[_allDataArrayaddObject:model];
[modelrelease];
NSLog(@"%@",_allDataArray);
}
// 1.创建UICollectionViewFlowLayout
UICollectionViewFlowLayout*flowLayout = [[UICollectionViewFlowLayoutalloc]init];
// 1.1设置每个Item的大小
flowLayout.itemSize=CGSizeMake(90,210);
// 1.2 设置每列最小间距
flowLayout.minimumInteritemSpacing=10;
// 1.3设置每行最小间距
flowLayout.minimumLineSpacing=10;
// 1.4设置滚动方向
flowLayout.scrollDirection=UICollectionViewScrollDirectionVertical;
// 1.5设置header区域大小
flowLayout.headerReferenceSize=CGSizeMake(self.view.bounds.size.width,50);
// 1.6设置footer区域大小
flowLayout.footerReferenceSize=CGSizeMake(self.view.bounds.size.width,50);
// 1.7 设置item内边距大小
flowLayout.sectionInset=UIEdgeInsetsMake(10,10,10,10);
// 2.创建UICollectionView
UICollectionView*collectionView = [[UICollectionViewalloc]initWithFrame:self.view.boundscollectionViewLayout:flowLayout];
// 3.设置数据源代理、collection代理
collectionView.dataSource=self;
collectionView.delegate=self;
[self.viewaddSubview:collectionView];
[collectionViewrelease];
[flowLayoutrelease];
collectionView.backgroundColor= [UIColorcolorWithRed:0.895green:1.000blue:0.656alpha:1.000];
// 4.注册cell的类型和重用标示符
[collectionViewregisterClass:[MyCellclass]forCellWithReuseIdentifier:@"cell"];
// 5.注册footer和header类型的重用标识符
[collectionViewregisterClass:[MyHeaderclass]forSupplementaryViewOfKind:UICollectionElementKindSectionHeaderwithReuseIdentifier:@"headerView"];
[collectionViewregisterClass:[MyFooterclass]forSupplementaryViewOfKind:UICollectionElementKindSectionFooter
withReuseIdentifier:@"footerView"];
}
#pragma mark - UICollectionViewDataSource Methods
#pragma mark 设置有多少个section
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView*)collectionView
{
return5;
}
#pragma mark 设置某个分组有多少行
- (NSInteger)collectionView:(UICollectionView*)collectionView numberOfItemsInSection:(NSInteger)section
{
return13;
}
#pragma mark 设置某个Item显示什么内容
- (UICollectionViewCell*)collectionView:(UICollectionView*)collectionView cellForItemAtIndexPath:(NSIndexPath*)indexPath
{
// 1.去重用队列中查找
MyCell*cell = [collectionViewdequeueReusableCellWithReuseIdentifier:@"cell"forIndexPath:indexPath];
// 2.使用
//CGFloat red = arc4random()% 256 / 255.0;
//CGFloat green = arc4random() % 256 / 255.0;
//CGFloat blue = arc4random() % 256 / 255.0;
//cell.backgroundColor = [UIColor colorWithRed:red green:green blue:blue alpha:1.0];
cell.label.text= [NSStringstringWithFormat:@"s = %ld r =%ld", indexPath.section, indexPath.row];
// 3.获取将要显示的模型
Model*model =_allDataArray[indexPath.row];
// 4.使用第三方获取图片并自动缓存
NSURL*imageUrl = [NSURLURLWithString:model.thumbURL];
[cell.imageViewsd_setImageWithURL:imageUrlplaceholderImage:[UIImageimageNamed:@"default_head_image@2x.png"]];
returncell;
}
#pragma mark 处理点击事件
- (void)collectionView:(UICollectionView*)collectionView didSelectItemAtIndexPath:(NSIndexPath*)indexPath
{
NSLog(@"我被点击了");
}
#pragma mark - UICollectionViewDelegateFlowLayout Method
#pragma mark 设置item的大小
- (CGSize)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath*)indexPath
{
returnCGSizeMake(90,120);
}
#pragma mark 设置footer和header
- (UICollectionReusableView*)collectionView:(UICollectionView*)collectionView viewForSupplementaryElementOfKind:(NSString*)kind atIndexPath:(NSIndexPath*)indexPath
{
if(kind ==UICollectionElementKindSectionHeader) {
// 去重用队列取可用的header
MyHeader*reusableView = [collectionViewdequeueReusableSupplementaryViewOfKind:kindwithReuseIdentifier:@"headerView"forIndexPath:indexPath];
// 使用
reusableView.headerImage.image= [UIImageimageNamed:@"屏幕快照 2014-0 9.30.50 9-11 上午.png"];
// 返回
returnreusableView;
}else{
// 去重用队列取可用的footer
MyFooter*reusableView = [collectionViewdequeueReusableSupplementaryViewOfKind:kindwithReuseIdentifier:@"footerView"forIndexPath:indexPath];
// 使用
reusableView.backgroundColor= [UIColorredColor];
// 返回
returnreusableView;
}
}
#pragma mark 设置header和footer高度
- (CGSize)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section
{
returnCGSizeMake(self.view.bounds.size.width,70);
}
- (CGSize)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section
{
returnCGSizeMake(self.view.bounds.size.width,70);
}
- (void)didReceiveMemoryWarning
{
[superdidReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)dealloc
{
[_allDataArrayrelease];
[superdealloc];
}
@end
总结：
集合视图UICollectionView和表示图UITableView很相似，可根据layout属性设置，显示单元格集合内容
UICollectionViewDataSource类作为集合视图的数据源，向集合视图提供数据。集合视图依赖于委托（Delegate）中定义的方法对用户进行响应
