UICollectionView的用法小结

UICollectionView的简单用法，具体可参考http://blog.csdn.net/majiakun1/article/details/17204693，有相关的三篇博客，个人感觉还不错，以下是个人的简单理解与应用，可以满足最简单的没有什么特殊展现形式的UICollectionView，后期鄙人也会不断的学习完善，以下是代码有Demo完整的展示，并且都附有注释详解，应该会很容易理解的，希望对各位有帮助，有啥不足的地方或者意见、建议，真心希望留言，咱们共同学习，一起进步，谢谢！

////  ViewController.m//  UICollertionViewDemo////  Created by Red_Coral on 15/7/30.//  Copyright (c) 2015年 Red_Coral. All rights reserved.//#import "ViewController.h"#define COLLECTIONVIEW_HEADERSECTION_IDENTIFIER @"collectionViewHeaderSctionView_indentifier"#define SCREEN_WIDTH  [UIScreen mainScreen].bounds.size.width@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegate>@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    UICollectionViewFlowLayout *flowLayout=[[UICollectionViewFlowLayout alloc] init];    [flowLayout setScrollDirection:UICollectionViewScrollDirectionVertical];        flowLayout.headerReferenceSize = CGSizeMake([[UIScreen mainScreen] bounds].size.width,100);    UICollectionView *collectionView = [[UICollectionView alloc]initWithFrame:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width, [[UIScreen mainScreen] bounds].size.height-2) collectionViewLayout:flowLayout];    //这侧UICollectionViewCell(此处也可以自定义的cell类)，但是后面的identifier和下面引用的必须要一致    [collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"UICollectionViewCell_identifier"];    //注册UICollectionView的section的Header或者footer，同样也要注意identifier的一致性    [collectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:COLLECTIONVIEW_HEADERSECTION_IDENTIFIER];    collectionView.backgroundColor = [UIColor redColor];    collectionView.dataSource = self;    collectionView.delegate = self;    collectionView.shouldGroupAccessibilityChildren = YES;    [self.view addSubview:collectionView];    }//确定UICollectionView每个章节有几个元素cell,- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {    return 10;}

//确定UICollectionView有几个章节，(这个方法可以省略)默认是一个- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {        return 2;}//制定每个cell将要在试图上展线成的样式及其内容- (UICollectionViewCell*)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {    static NSString *tempStr = @"UICollectionViewCell_identifier";    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:tempStr forIndexPath:indexPath];    [cell sizeToFit];    if (!cell) {        NSLog(@"无法创建CollectionViewCell时打印，自定义的cell就不可能进来了。");    }    cell.backgroundColor = [UIColor greenColor];        return cell;}/* *1、此处为Supplementary Views 追加视图 （类似Header或者Footer） *2、用到的identifier需要和注册的一致（可在此处添加自定义） */- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {        NSLog(@"kind: %@",kind);        UICollectionReusableView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:                                            UICollectionElementKindSectionHeader withReuseIdentifier:COLLECTIONVIEW_HEADERSECTION_IDENTIFIER forIndexPath:indexPath];    headerView.backgroundColor = [UIColor yellowColor];    return headerView;}//确定每个cell的宽和高- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{    //cell的宽、高    return CGSizeMake((SCREEN_WIDTH-3)/4., (SCREEN_WIDTH-3)/4.);}//定义每个UICollectionView的cell的layout情况，ps:你可以将下面的值意义改变，看看效果-(UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{    return UIEdgeInsetsMake(10, 0, 0, 0);}//定义每个UICollectionView items列与列之间的间隔- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {        return 1;}//items行与行之间的间隔- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {    return 1;}#pragma mark - UICollectionViewDelegate//UICollectionView被选中时调用的方法-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{    NSLog(@"选择第%ld章%ld个cell",(long)indexPath.section,(long)indexPath.row);}//返回这个UICollectionView是否可以被选择-(BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath{    return YES;}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    }@end