UICollectionView的简单使用

其他 2018-10-20 16:11:13 阅读次数: 0

项目应用：

#import "HomeGroupOrderCell.h"

#import "HomeGroupOrderCollectionViewCell.h"

@interface HomeGroupOrderCell ()<UICollectionViewDelegate,UICollectionViewDataSource>

@property (weak, nonatomic) IBOutlet UICollectionView *collectionView;

@end

@implementation HomeGroupOrderCell

- (void)awakeFromNib {

    [super awakeFromNib];

    UICollectionViewFlowLayout *layout = [UICollectionViewFlowLayout new];

//移动方向(纵向移动)

//    layout.scrollDirection = UICollectionViewScrollDirectionVertical;

//同一行每个collectionCell之间的间距

//    layout.minimumLineSpacing = 5;

//同一个Section下，每行之间的间距

//    layout.minimumInteritemSpacing = 5;

    [self.collectionView setCollectionViewLayout:layout];

    

    self.collectionView.scrollEnabled = NO;

    self.collectionView.scrollsToTop = NO;

//是否显示移动条

    self.collectionView.showsVerticalScrollIndicator = NO;

    self.collectionView.showsHorizontalScrollIndicator = NO;

    //    [self.collectionView setContentSize:CGSizeMake(self.dataArray.count*((ScreenWidth-40)/3+5), 0)];

//    self.collectionView.backgroundColor = COLOR_HEX(@"#f3f3f3");

    

    self.collectionView.delegate=self;

    self.collectionView.dataSource=self;

    

//注册CollectionViewCell

    [self.collectionView registerNib:[UINibnibWithNibName:@"HomeGroupOrderCollectionViewCell" bundle:[NSBundlemainBundle]] forCellWithReuseIdentifier:@"groupCell"];

}

#pragma mark --- UICollectionViewDataSource

//分区数

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView*)collectionView{

    if (self.dataArray.count>0) {

        return (self.dataArray.count+1)/2;

    }else{

        return 0;

    }

}

//设置每个分区的item个数

-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section

{

    if (self.dataArray.count%2 == 0) {

        return 2;

    }else{

        if (section == (self.dataArray.count+1)/2) {

            return 1;

        }else{

            return 2;

        }

    }

}

- (__kindof UICollectionViewCell *)collectionView:(UICollectionView*)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{

    HomeGroupOrderCollectionViewCell* cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"groupCell" forIndexPath:indexPath];

//    [cell setContentWithProductInfo:self.dataArray[indexPath.row] IndexPath:indexPath];

//    NSString *goods_id = self.dataArray[indexPath.row][@"goods_id"];

//    cell.orderNowBlock = ^(NSIndexPath *index) {

//        !self.orderNowBlock? :self.orderNowBlock(index,goods_id);

//    };

    return cell;

}

//item的size

-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{

    

    return CGSizeMake((ScreenWidth-5)/2, (ScreenWidth-5)/2+9+37+15+25+17);

    

}

//用于调节每个section的上左下右的距离

-(UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section

{

    return UIEdgeInsetsMake(5, 0, 0, 0);//分别为上、左、下、右

}

////同一个section中不同的行之间的行间距

//- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section

//{

//    return 5;

//}

//每个item之间的间距

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section

{

    return 0;

}

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{

//    NSString *goods_id = self.dataArray[indexPath.row][@"goods_id"];

//    !self.goToGoodsDetailBlock? :self.goToGoodsDetailBlock(goods_id);

}

UICollectionView的应用：

 

－. 布局

UICollectionViewFlowLayout流水布局

  1. 通过UICollectionViewFlowLayout对象进行布局( 如果布局的尺寸是固定的，例如：item的尺寸大小都是固定，可以使用全局属性，即设置下文中layout ) 
     UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
 // 1.设置列间距
 layout.minimumInteritemSpacing = 1;
 // 2.设置行间距
 layout.minimumLineSpacing = 1;
 // 3.设置每个item的大小
 layout.itemSize = CGSizeMake(50, 50);
 // 4.设置Item的估计大小,用于动态设置item的大小，结合自动布局（self-sizing-cell）
 layout.estimatedItemSize = CGSizeMake(320, 60);
 // 5.设置布局方向
 layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
 // 6.设置头视图尺寸大小
 layout.headerReferenceSize = CGSizeMake(50, 50);
 // 7.设置尾视图尺寸大小
 layout.footerReferenceSize = CGSizeMake(50, 50);
 // 8.设置分区(组)的EdgeInset（四边距）
 layout.sectionInset = UIEdgeInsetsMake(10, 20, 30, 40);
 // 9.10.设置分区的头视图和尾视图是否始终固定在屏幕上边和下边
 layout.sectionFootersPinToVisibleBounds = YES;
 layout.sectionHeadersPinToVisibleBounds = YES;
  2. 通过遵守UICollectionViewDelegateFlowLayout实现代理方法来布局（非固定情况则需要通过数据源方法）
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath;
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section;
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section;
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section;
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section;
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section;

二. 数据源方法

//设置分区数（必须实现）
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1;
}

//设置每个分区的item个数
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{ 
    return 5;  
}

//设置返回每个item的属性必须实现）
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [self.collection dequeueReusableCellWithReuseIdentifier:ID forIndexPath:indexPath];
    return cell;
}

//对头视图或者尾视图进行设置
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
    NSString *identifier;

    if ([kind isEqualToString:UICollectionElementKindSectionHeader]) {
        identifier = @"headerView";
    } else {
        identifier = @"footerView";
    }
    UICollectionReusableView *view = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:identifier forIndexPath:indexPath];
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 10, 120, 30)];
    [view addSubview:label];

    if (indexPath.section == 0) {
        label.text = @"section1";
    }else {
        label.text = @"section2";
    }
    if ([kind isEqualToString:UICollectionElementKindSectionHeader]) {
        view.backgroundColor = [UIColor redColor];
    } else {
        view.backgroundColor = [UIColor purpleColor];

    }
    return view;
}

//是否允许移动Item
- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(9_0){
    return YES;
}

//移动Item时触发的方法
- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath NS_AVAILABLE_IOS(9_0); {

}

三. 常用到的代理方法

//是否允许某个Item的高亮，返回NO，则不能进入高亮状态
- (BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath; {
    return YES;
}

//当item高亮时触发的方法
- (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath; {

}

//结束高亮状态时触发的方法
- (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath; {

}

//是否可以选中某个Item，返回NO，则不能选中
- (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath; {
    return YES;
}

//是否可以取消选中某个Item
- (BOOL)collectionView:(UICollectionView *)collectionView shouldDeselectItemAtIndexPath:(NSIndexPath *)indexPath; {
    return YES;
}

//已经选中某个item时触发的方法
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath; {

}

//取消选中某个Item时触发的方法
- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath; {

}

//将要加载某个Item时调用的方法
- (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(8_0); {

}

//将要加载头尾视图时调用的方法
- (void)collectionView:(UICollectionView *)collectionView willDisplaySupplementaryView:(UICollectionReusableView *)view forElementKind:(NSString *)elementKind atIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(8_0); {

}

//已经展示某个Item时触发的方法
- (void)collectionView:(UICollectionView *)collectionView didEndDisplayingCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath; {

}

//已经展示某个头尾视图时触发的方法
- (void)collectionView:(UICollectionView *)collectionView didEndDisplayingSupplementaryView:(UICollectionReusableView *)view forElementOfKind:(NSString *)elementKind atIndexPath:(NSIndexPath *)indexPath; {

}

//这个方法设置是否展示长按菜单
- (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath; {
    return YES;
}

//这个方法用于设置要展示的菜单选项
- (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(nullable id)sender; {
    return YES;
}

//这个方法用于实现点击菜单按钮后的触发方法,通过测试，只有copy，cut和paste三个方法可以使用
- (void)collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(nullable id)sender; {
    //通过下面的方式可以将点击按钮的方法名打印出来：
    NSLog(@"%@",NSStringFromSelector(action));
}

//collectionView进行重新布局时调用的方法
//- (nonnull UICollectionViewTransitionLayout *)collectionView:(UICollectionView *)collectionView transitionLayoutForOldLayout:(UICollectionViewLayout *)fromLayout newLayout:(UICollectionViewLayout *)toLayout; {
//
//}

四. collectionView的属性和相关方法

//通过一个布局策略初识化CollectionView
    - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout;

    //获取和设置collection的layout
    @property (nonatomic, strong) UICollectionViewLayout *collectionViewLayout;

    //数据源和代理
    @property (nonatomic, weak, nullable) id <UICollectionViewDelegate> delegate;
    @property (nonatomic, weak, nullable) id <UICollectionViewDataSource> dataSource;

    //从一个class或者xib文件进行cell(item)的注册
    - (void)registerClass:(nullable Class)cellClass forCellWithReuseIdentifier:(NSString *)identifier;
    - (void)registerNib:(nullable UINib *)nib forCellWithReuseIdentifier:(NSString *)identifier;

    //下面两个方法与上面相似，这里注册的是头视图或者尾视图的类
    //其中第二个参数是设置 头视图或者尾视图 系统为我们定义好了这两个字符串
    //UIKIT_EXTERN NSString *const UICollectionElementKindSectionHeader NS_AVAILABLE_IOS(6_0);
    //UIKIT_EXTERN NSString *const UICollectionElementKindSectionFooter NS_AVAILABLE_IOS(6_0);
    - (void)registerClass:(nullable Class)viewClass forSupplementaryViewOfKind:(NSString *)elementKind withReuseIdentifier:(NSString *)identifier;
    - (void)registerNib:(nullable UINib *)nib forSupplementaryViewOfKind:(NSString *)kind withReuseIdentifier:(NSString *)identifier;

    //这两个方法是从复用池中取出cell或者头尾视图
    - (__kindof UICollectionViewCell *)dequeueReusableCellWithReuseIdentifier:(NSString *)identifier forIndexPath:(NSIndexPath *)indexPath;
    - (__kindof UICollectionReusableView *)dequeueReusableSupplementaryViewOfKind:(NSString *)elementKind withReuseIdentifier:(NSString *)identifier forIndexPath:(NSIndexPath *)indexPath;

    //设置是否允许选中 默认yes
    @property (nonatomic) BOOL allowsSelection;

    //设置是否允许多选 默认no
    @property (nonatomic) BOOL allowsMultipleSelection;

    //获取所有选中的item的位置信息
    - (nullable NSArray<NSIndexPath *> *)indexPathsForSelectedItems;

    //设置选中某一item，并使视图滑动到相应位置，scrollPosition是滑动位置的相关参数，如下：
    /*
     typedef NS_OPTIONS(NSUInteger, UICollectionViewScrollPosition) {
     //无
     UICollectionViewScrollPositionNone                 = 0,
     //垂直布局时使用的 对应上中下
     UICollectionViewScrollPositionTop                  = 1 << 0,
     UICollectionViewScrollPositionCenteredVertically   = 1 << 1,
     UICollectionViewScrollPositionBottom               = 1 << 2,
     //水平布局时使用的  对应左中右
     UICollectionViewScrollPositionLeft                 = 1 << 3,
     UICollectionViewScrollPositionCenteredHorizontally = 1 << 4,
     UICollectionViewScrollPositionRight                = 1 << 5
     };
     */
    - (void)selectItemAtIndexPath:(nullable NSIndexPath *)indexPath animated:(BOOL)animated scrollPosition:(UICollectionViewScrollPosition)scrollPosition;

    //将某一item取消选中
    - (void)deselectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated;

    //重新加载数据
    - (void)reloadData;

    //下面这两个方法，可以重新设置collection的布局，后面的方法多了一个布局完成后的回调，iOS7后可以用
    //使用这两个方法可以产生非常炫酷的动画效果
    - (void)setCollectionViewLayout:(UICollectionViewLayout *)layout animated:(BOOL)animated;
    - (void)setCollectionViewLayout:(UICollectionViewLayout *)layout animated:(BOOL)animated completion:(void (^ __nullable)(BOOL finished))completion NS_AVAILABLE_IOS(7_0);

    //下面这些方法更加强大，我们可以对布局更改后的动画进行设置
    //这个方法传入一个布局策略layout，系统会开始进行布局渲染，返回一个UICollectionViewTransitionLayout对象
    //这个UICollectionViewTransitionLayout对象管理动画的相关属性，我们可以进行设置
    - (UICollectionViewTransitionLayout *)startInteractiveTransitionToCollectionViewLayout:(UICollectionViewLayout *)layout completion:(nullable UICollectionViewLayoutInteractiveTransitionCompletion)completion NS_AVAILABLE_IOS(7_0);
    //准备好动画设置后，我们需要调用下面的方法进行布局动画的展示，之后会调用上面方法的block回调
    - (void)finishInteractiveTransition NS_AVAILABLE_IOS(7_0);
    //调用这个方法取消上面的布局动画设置，之后也会进行上面方法的block回调
    - (void)cancelInteractiveTransition NS_AVAILABLE_IOS(7_0);

    //获取分区数
    - (NSInteger)numberOfSections;

    //获取某一分区的item数
    - (NSInteger)numberOfItemsInSection:(NSInteger)section;

    //下面两个方法获取item或者头尾视图的layout属性，这个UICollectionViewLayoutAttributes对象
    //存放着布局的相关数据，可以用来做完全自定义布局，后面博客会介绍
    - (nullable UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath;
    - (nullable UICollectionViewLayoutAttributes *)layoutAttributesForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath;

    //获取某一点所在的indexpath位置
    - (nullable NSIndexPath *)indexPathForItemAtPoint:(CGPoint)point;

    //获取某个cell所在的indexPath
    - (nullable NSIndexPath *)indexPathForCell:(UICollectionViewCell *)cell;

    //根据indexPath获取cell
    - (nullable UICollectionViewCell *)cellForItemAtIndexPath:(NSIndexPath *)indexPath;

    //获取所有可见cell的数组
    - (NSArray<__kindof UICollectionViewCell *> *)visibleCells;

    //获取所有可见cell的位置数组
    - (NSArray<NSIndexPath *> *)indexPathsForVisibleItems;

    //下面三个方法是iOS9中新添加的方法，用于获取头尾视图
    - (UICollectionReusableView *)supplementaryViewForElementKind:(NSString *)elementKind atIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(9_0);
    - (NSArray<UICollectionReusableView *> *)visibleSupplementaryViewsOfKind:(NSString *)elementKind NS_AVAILABLE_IOS(9_0);
    - (NSArray<NSIndexPath *> *)indexPathsForVisibleSupplementaryElementsOfKind:(NSString *)elementKind NS_AVAILABLE_IOS(9_0);

    //使视图滑动到某一位置，可以带动画效果
    - (void)scrollToItemAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(UICollectionViewScrollPosition)scrollPosition animated:(BOOL)animated;

    //下面这些方法用于动态添加，删除，移动某些分区获取items
    - (void)insertSections:(NSIndexSet *)sections;
    - (void)deleteSections:(NSIndexSet *)sections;
    - (void)reloadSections:(NSIndexSet *)sections;
    - (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection;

    - (void)insertItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;
    - (void)deleteItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;
    - (void)reloadItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;
    - (void)moveItemAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath;

五，自定义布局

UICollectionViewDelegateFlowLayout可以继承这个自定义

自定义UICollectionViewLayout(抽象类):

- (void)prepareLayout
{
    [super prepareLayout];
}

-(UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath
{
    NSMutableDictionary *dict;
    dict[@"0"] = @1;
    dict[@"1"] = @2;
    UICollectionViewLayoutAttributes *attrs = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
    attrs.transform3D = CATransform3DMakeRotation(arc4random_uniform(M_1_PI), 1, 1, 1);
    // zIndex越大，就越在上面
    attrs.zIndex =  [self.collectionView numberOfItemsInSection:indexPath.section]-indexPath.item;
    @property (nonatomic) CGRect frame;
    @property (nonatomic) CGPoint center;
    @property (nonatomic) CGSize size;
    @property (nonatomic) CATransform3D transform3D;
    @property (nonatomic) CGRect bounds NS_AVAILABLE_IOS(7_0);
    @property (nonatomic) CGAffineTransform transform NS_AVAILABLE_IOS(7_0);
    @property (nonatomic) CGFloat alpha;
    @property (nonatomic) NSInteger zIndex; // default is 0
    @property (nonatomic, getter=isHidden) BOOL hidden; // As an optimization, UICollectionView might not create a view for items whose hidden attribute is YES
    @property (nonatomic, strong) NSIndexPath *indexPath;    return attrs;
    //    ABS(1-2);绝对值     CGRectIntersectsRect(<#CGRect rect1#>, <#CGRect rect2#>) 这要和rect1相交就都算；
}

- (NSArray<UICollectionViewLayoutAttributes *> *)layoutAttributesForElementsInRect:(CGRect)rect
{
    NSMutableArray *array = [NSMutableArray array];
    NSInteger count = [self.collectionView numberOfItemsInSection:0];
    for (int i=0; i<count; i++) {
        UICollectionViewLayoutAttributes *attrs = [self layoutAttributesForItemAtIndexPath:[NSIndexPath indexPathForItem:i inSection:0]];
        [array addObject:attrs];
    }
    return array;
}

- (BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)newBounds
{
    return YES;
}
从写方法计算contentsize

注：参考自http://my.oschina.net/u/2340880/blog/522682

著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

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