下午说了他最基础的使用方法，现在说一下详细的使用方法，通过自定义cell，来实现个性化点的UICollectionView
项目Demo下载
GitHub下载地址：https://github.com/DamonHu/HudongBlogDemo/tree/master/collectionDemo
项目说明
1、通过自定义cell来实现自己的UICollectionView中一个一个的item
建立一个MyCollectionViewCell类，这个类就是自定义的，简单的实现方法
MyCollectionViewCell.h文件
#import <UIKit/UIKit.h>
@interface MyCollectionViewCell : UICollectionViewCell
@property (strong,nonatomic) UILabel* myLabel;
@property (strong,nonatomic) UIImageView *myImgView;
@endMyCollectionViewCell.m文件
#import "MyCollectionViewCell.h"
@implementation MyCollectionViewCell
//重写初始化方法
-(id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.myImgView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 60, 60)];
[self setCellImage:@"demo.jpg"];
[self.contentView addSubview:self.myImgView];
self.myLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 70, 70, 40)];
[self setCellLabelText:@"demo"];
[self.contentView addSubview:self.myLabel];
//可以设置圆角
self.layer.cornerRadius = 30;
}
return self;
}
//更改图片
-(void)setCellImage:(NSString*)ImgName
{
[self.myImgView setImage:[UIImage imageNamed:ImgName]];
}
//更改文字
-(void)setCellLabelText:(NSString*)text
{
[self.myLabel setText:text];
}
@end这个类主要就是图片和文字，并且设置成圆角的cell，更多个性化需要自己来写
2、使用这个cell来定义UICollectionView
在ViewController中加载
ViewController.h文件，这个文件就是声明一个CollectionView和暂存数据的一个可变数组Array
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
@property(strong,nonatomic)UICollectionView * myCollection;
@property(strong,nonatomic)NSMutableArray * myArray;
@endViewController.m文件
- (void)viewDidLoad {
[super viewDidLoad];
self.myArray = [NSMutableArray arrayWithObjects:@"1",@"1",@"1",@"1",@"1",@"1",@"1",@"1",@"1", nil];
//定义flowLayout
UICollectionViewFlowLayout *flowLayout=[[UICollectionViewFlowLayout alloc] init];
[flowLayout setScrollDirection:UICollectionViewScrollDirectionVertical];
//可选定义item的其他选项，在UICollectionViewFlowLayout类里面，也可以在代理中单独指定
flowLayout.itemSize = CGSizeMake(100, 100);
flowLayout.sectionInset = UIEdgeInsetsMake(20, 20, 20, 20);
flowLayout.headerReferenceSize = CGSizeMake(100, 100);
flowLayout.footerReferenceSize = CGSizeMake(100, 100);
self.myCollection = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height) collectionViewLayout:flowLayout];
self.myCollection.delegate = self;
self.myCollection.dataSource = self;
[self.myCollection setBackgroundColor:[UIColor redColor]];
//注册cell
[self.myCollection registerClass:[MyCollectionViewCell class] forCellWithReuseIdentifier:CELL_INDI];
//注册sectionHeader和footer，以调用- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
[self.myCollection registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:HEADER_INDI];
[self.myCollection registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:FOOTER_INDI];
[self.view addSubview:self.myCollection];
}在ViewDidLoad中，把这个collectionView加载到视图中，其中flowLayout是定义的一个一个item的排列顺序，跳转类进去可以看到它有这几个参数
@property (nonatomic) CGFloat minimumLineSpacing;
@property (nonatomic) CGFloat minimumInteritemSpacing;
@property (nonatomic) CGSize itemSize;
@property (nonatomic) CGSize estimatedItemSize NS_AVAILABLE_IOS(8_0); // defaults to CGSizeZero - setting a non-zero size enables cells that self-size via -preferredLayoutAttributesFittingAttributes:
@property (nonatomic) UICollectionViewScrollDirection scrollDirection; // default is UICollectionViewScrollDirectionVertical
@property (nonatomic) CGSize headerReferenceSize;
@property (nonatomic) CGSize footerReferenceSize;
@property (nonatomic) UIEdgeInsets sectionInset;这几个参数都是可以用来微调Cell的大小、样式、排列方式的，当然，如果是要通用的样式，那么直接修改这几个参数就可以了，如果是要根据不同的Section和row来实现一个collectionView不同的cell的样式不同的话，需要把这个类加上UICollectionViewDelegateFlowLayout这个代理，
3、通过代理方法来个性化样式
他的代理方法可以按照demo中的个性话设置。在UICollectionViewDelegateFlowLayout代理方法中。
通过实现它的代理方式，来分不同的section和row来个性话，就像下面这样，几乎他的每一个参数都可以在代理中个性话定制。
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
//自定义item大小
if (indexPath.section == 1 && indexPath.row == 1) {
return CGSizeMake(20, 20);
}
else
return CGSizeMake(100, 100);
}
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
//自定义item的UIEdgeInsets
if (section == 1) {
return UIEdgeInsetsMake(90, 90, 90, 90);
}
return UIEdgeInsetsMake(20, 20, 20, 20);
}UICollectionViewDataSource是定义cell的样式，和tableview一样
#pragma mark - UICollectionViewDataSource
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
if (section == 0) {
return self.myArray.count;
}
return 10;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MyCollectionViewCell * cell = [collectionView dequeueReusableCellWithReuseIdentifier:CELL_INDI forIndexPath:indexPath];
cell.backgroundColor = [UIColor blueColor];
return cell;
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 3;
}
//和UITableView类似，UICollectionView也可设置段头段尾，设置头和尾的大小才会调用这个函数
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
if([kind isEqualToString:UICollectionElementKindSectionHeader])
{
UICollectionReusableView *headerView = [self.myCollection dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:HEADER_INDI forIndexPath:indexPath];
if(headerView == nil)
{
headerView = [[UICollectionReusableView alloc] init];
}
headerView.backgroundColor = [UIColor whiteColor];
return headerView;
}
else if([kind isEqualToString:UICollectionElementKindSectionFooter])
{
UICollectionReusableView *footerView = [self.myCollection dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:FOOTER_INDI forIndexPath:indexPath];
if(footerView == nil)
{
footerView = [[UICollectionReusableView alloc] init];
}
footerView.backgroundColor = [UIColor blackColor];
return footerView;
}
return nil;
}
//下面这两个函数ios9.0不能用
- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath
{
// 指定第一个不让移动，其他的让移动
if (indexPath.row ==0) {
return false;
}
else
return true;
}
- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath
{
//哪个item移动了
NSLog(@"%ld,%ld",(long)sourceIndexPath.row,(long)sourceIndexPath.section);
}在UICollectionViewDelegate可以控制逻辑等，比如高亮，剪切等
#pragma mark - UICollectionViewDelegate
//是否高亮
- (BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath
{
return true;
}
// 点击高亮
- (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
cell.backgroundColor = [UIColor greenColor];
}
//选择的哪个
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(@"%ld,%ld",(long)indexPath.row,(long)indexPath.section);
}
//不选择哪个了，就变成原来的颜色
- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
cell.backgroundColor = [UIColor blueColor];
}
//当松开鼠标的时候会调用
//- (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath
//{
// UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
// cell.backgroundColor = [UIColor blueColor];
//}
//下面这三个函数是长按之后，显示剪切，复制，粘贴按钮
- (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath
{
return true;
}
- (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(nullable id)sender
{
return true;
}
- (void)collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(nullable id)sender
{
//打印操作名称
NSLog(@"%@",NSStringFromSelector(action));
//删除操作
// [collectionView performBatchUpdates:^{
// [collectionView deleteItemsAtIndexPaths:[NSArray arrayWithObject:indexPath]];
// } completion:nil];
//或者这样 注意，删除的这个indexpath的item数必须要同步更新，并且不能影响其他section的item数，所以最好就是删除的这个单独写一个数组。否则删除会直接报错，插入也是
//删除
if ([NSStringFromSelector(action) isEqualToString:@"cut:"]) {
if (indexPath.section == 0) {
[self.myArray removeObjectAtIndex:indexPath.row];
[collectionView deleteItemsAtIndexPaths:[NSArray arrayWithObject:indexPath]];
}
}
//插入
if ([NSStringFromSelector(action) isEqualToString:@"copy:"]) {
if (indexPath.section == 0) {
[self.myArray addObject:@"1"];
[collectionView insertItemsAtIndexPaths:[NSArray arrayWithObject:indexPath]];
}
}
}然后即可达到这种显示效果：
参考文章
版权属于：东哥笔记
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