UIKit 框架之UICollectionView-白红宇

1.自定义UICollectionViewCell

在myCollectionViewCell.h中声明两个属性

////  myCollectionViewCell.h//  UICollectionView////  Created by City--Online on 15/5/25.//  Copyright (c) 2015年 XQB. All rights reserved.// #import 
    
      @interface myCollectionViewCell : UICollectionViewCell@property(nonatomic,strong) UIImageView *myImageView;@property(nonatomic,strong) UILabel *nameLabel;@end

在myCollectionViewCell.m中绘制视图

////  myCollectionViewCell.m//  UICollectionView////  Created by City--Online on 15/5/25.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "myCollectionViewCell.h" @implementation myCollectionViewCell-(void)layoutSubviews{    self.myImageView.frame=CGRectMake(0, 0, self.contentView.frame.size.width,80);    [self.contentView addSubview:self.myImageView];         self.nameLabel.frame = CGRectMake(0,80 , self.contentView.frame.size.width, 40);    [self.contentView addSubview:self.nameLabel];    [self.nameLabel setBackgroundColor:[UIColor cyanColor]]; }@end

2.实例化UICollectionView,并实现它的代理方法

////  ViewController.m//  UICollectionView////  Created by City--Online on 15/5/25.//  Copyright (c) 2015年 XQB. All rights reserved.// #import "ViewController.h"#import "myCollectionViewCell.h" @interface ViewController ()
    
     @property(nonatomic,strong) UICollectionView *collectionView;@end @implementation ViewController - (void)viewDidLoad {    [super viewDidLoad];         //UICollectionViewLayout可以说是UICollectionView的大脑和中枢，它负责了将各个cell、Supplementary View和Decoration Views进行组织，为它们设定各自的属性    //Layout决定了UICollectionView是如何显示在界面上的。在展示之前，一般需要生成合适的UICollectionViewLayout子类对象，并将其赋予CollectionView的collectionViewLayout属性    UICollectionViewFlowLayout  *collectionViewFlowLayout=[[UICollectionViewFlowLayout alloc]init];    collectionViewFlowLayout.minimumInteritemSpacing=0.0;    collectionViewFlowLayout.minimumLineSpacing=0.0;    collectionViewFlowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;    collectionViewFlowLayout.sectionInset = UIEdgeInsetsMake(0.0, 0.0, 0, 0.0);    //它定义了每一个item的大小。通过设定itemSize可以全局地改变所有cell的尺寸，如果想要对某个cell制定尺寸，可以使用-collectionView:layout:sizeForItemAtIndexPath:方法    collectionViewFlowLayout.itemSize=CGSizeMake(120, 120);    collectionViewFlowLayout.estimatedItemSize=CGSizeMake(120, 120);    //由属性scrollDirection确定scroll view的方向，将影响Flow Layout的基本方向和由header及footer确定的section之间的宽度    collectionViewFlowLayout.scrollDirection=UICollectionViewScrollDirectionVertical;    //Header和Footer尺寸 同样地分为全局和部分。需要注意根据滚动方向不同，header和footer的高和宽中只有一个会起作用。垂直滚动时section间宽度为该尺寸的高，而水平滚动时为宽度起作用    collectionViewFlowLayout.headerReferenceSize=CGSizeMake(100, 40);    collectionViewFlowLayout.footerReferenceSize=CGSizeMake(100, 40);         _collectionView=[[UICollectionView alloc]initWithFrame:self.view.bounds collectionViewLayout:collectionViewFlowLayout];    _collectionView.backgroundColor=[UIColor whiteColor];    _collectionView.delegate=self;    _collectionView.dataSource=self;    _collectionView.allowsSelection=YES;    _collectionView.allowsMultipleSelection=YES;         // 注册相关类    [_collectionView registerClass:[myCollectionViewCell class] forCellWithReuseIdentifier:@"cell"];    [_collectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"Header"];    [_collectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"Footer"];    //也可以用Nib//    [[_collectionView registerNib:<#(UINib *)#> forCellWithReuseIdentifier:<#(NSString *)#>]//    _collectionView registerNib:<#(UINib *)#> forSupplementaryViewOfKind:<#(NSString *)#> withReuseIdentifier:<#(NSString *)#>    [self.view addSubview:_collectionView];     } //UICollectionViewDataSource  代理//每节单元格数- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{    if (section==0) {        return 6;    }    else    {         return 4;    }    } //节数- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{    return 2;}//单元格- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{    myCollectionViewCell *cell =[collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];         cell.backgroundColor = [UIColor colorWithRed:arc4random()%256/ 255.0  green:arc4random()%256 / 255.0 blue:arc4random()% 256 / 255.0  alpha:1];    cell.myImageView=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"1.png"]];    cell.nameLabel=[[UILabel alloc]init];    cell.nameLabel.text=[NSString stringWithFormat:@"%ld %ld",indexPath.section,indexPath.row];    return cell;     }//节头节尾- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath{    if ([kind isEqualToString: UICollectionElementKindSectionFooter]) {        UICollectionReusableView *footer=[collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"Footer" forIndexPath:indexPath];        footer.backgroundColor=[UIColor yellowColor];        UILabel *label=[[UILabel alloc]initWithFrame:CGRectMake(0, 0, 100, 40)];        label.text=@"label";        label.textAlignment=NSTextAlignmentCenter;        [footer addSubview:label];        return footer;    }    else    {        UICollectionReusableView *Header=[collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"Header" forIndexPath:indexPath];        Header.backgroundColor=[UIColor blueColor];        return Header;             }}//UICollectionViewDelegate 代理//选中时是否高亮- (BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath{    if (indexPath.row%2==0) {        return YES;    }    return NO;}//选中高亮显示后- (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath{    NSLog(@"didHighlightItemAtIndexPath");}// 允许被选中- (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath{    return YES;}//允许被取消- (BOOL)collectionView:(UICollectionView *)collectionView shouldDeselectItemAtIndexPath:(NSIndexPath *)indexPath{    return YES;}//选中某个单元格- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{     NSLog(@"didSelectItemAtIndexPath section=%ld row=%ld",indexPath.section,indexPath.row);}//取消某个单元格- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath{    NSLog(@"didDeselectItemAtIndexPath section=%ld row=%ld",indexPath.section,indexPath.row);}//高亮不显示- (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath{         NSLog(@"didUnhighlightItemAtIndexPath");}//即将展示UICollectionViewCell- (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath{    NSLog(@"willDisplayCell");}//即将显示section的footer和header- (void)collectionView:(UICollectionView *)collectionView willDisplaySupplementaryView:(UICollectionReusableView *)view forElementKind:(NSString *)elementKind atIndexPath:(NSIndexPath *)indexPath{     NSLog(@"willDisplaySupplementaryView");}//UICollectionViewCell显示完成- (void)collectionView:(UICollectionView *)collectionView didEndDisplayingCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath{    NSLog(@"didEndDisplayingCell");}//显示section的footer和header完成- (void)collectionView:(UICollectionView *)collectionView didEndDisplayingSupplementaryView:(UICollectionReusableView *)view forElementOfKind:(NSString *)elementKind atIndexPath:(NSIndexPath *)indexPath{     NSLog(@"didEndDisplayingSupplementaryView");}//是否显示 copy、cut、paste等- (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath{    return YES;}//是否显示action辅助功能- (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender{    SEL sel=@selector(copy:);    if (sel==action) {        return YES;    }    return NO;}//判断选择的是什么action- (void)collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender{    SEL sel=@selector(copy:);    if (sel==action) {        NSLog(@"aaaaa");    }    } - (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.} @end

在上面的Header、Footer没有自定义，其实也可以自定义。UICollectionView中的一些方法和UITableView中的类似,这里就不举例了。