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UICollectionView的使用

2024-07-12 07:32:09   213人阅读

文件结构：

一：先定义cell，这里是Cell类，继承自UICollectionViewCell，用xib画出cell

CollectionCell.h

1 #import <UIKit/UIKit.h>2 3 @interface CollectionCell : UICollectionViewCell4 5 @end

CollectionCell.c

 1 #import "CollectionCell.h" 2  3 @implementation CollectionCell 4  5 - (id)initWithFrame:(CGRect)frame 6 { 7     self = [super initWithFrame:frame]; 8     if (self) 9     {10         // 初始化时加载collectionCell.xib文件11         NSArray *arrayOfViews = [[NSBundle mainBundle] loadNibNamed:@"CollectionCell" owner:self options:nil];12         13         // 如果路径不存在，return nil14         if (arrayOfViews.count < 1)15         {16             return nil;17         }18         // 如果xib中view不属于UICollectionViewCell类，return nil19         if (![[arrayOfViews objectAtIndex:0] isKindOfClass:[UICollectionViewCell class]])20         {21             return nil;22         }23         // 加载nib24         self = [arrayOfViews objectAtIndex:0];25     }26     return self;27 }

CollectionCell.xib

画出cell：

设置Cell大小：

设置Identifier：

设置Class：

二：UICollectionViewController

1.CollectionViewController.h

1 #import <UIKit/UIKit.h>2 #import "CollectionCell.h"3 4 @interface CollectionViewController : UICollectionViewController5 6 7 @end

2.CollectionViewController.c

 1 #import "CollectionViewController.h" 2  3 @interface CollectionViewController () 4  5 @end 6  7 @implementation CollectionViewController 8  9 - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil10 {11     self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];12     if (self) {13         // Custom initialization14     }15     return self;16 }17 18 - (void)viewDidLoad19 {20     [super viewDidLoad];21     // Do any additional setup after loading the view from its nib.22 23     self.collectionView.dataSource = self;24     self.collectionView.delegate = self;25 }26 27 - (void)didReceiveMemoryWarning28 {29     [super didReceiveMemoryWarning];30     // Dispose of any resources that can be recreated.31 }32 33 -(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section34 {35     return 4;36 }37 38 -(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath39 {40     [self.collectionView registerClass:[CollectionCell class] forCellWithReuseIdentifier:@"CollectionCell"];41     42     CollectionCell *cell = (CollectionCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"CollectionCell" forIndexPath:indexPath];43     44     45     return cell;46 }47 48 //- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath49 //{50 //    CGFloat width = indexPath.row * 50;51 //    CGFloat height = indexPath.row * 50;52 //    return CGSizeMake(width,height);53 //    54 //}55 56 @end

3.CollectionViewController.xib:

结构：

删除原来的view，拖一个collectionView进来

设置file‘s owner

custom class

cell大小及间隙

outlet：

常见错误：

1.只有collectionView，没有Cell显示出来，那么重写自定义Cell类的 - (id)initWithFrame:(CGRect)frame 方法，从nib加载或者自定义。

2.Xcode运行时报错：

UICollectionElementKindCell with identifier CollectionCell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard

检查有没有注册identifier：在viewDidLoad方法里加入：

[self.collectionView registerClass:[CollectionCell class] forCellWithReuseIdentifier:@"CollectionCell"];

3.

‘NSInternalInconsistencyException‘, reason: ‘-[UIViewController _loadViewFromNibNamed:bundle:] loaded the "CollectionViewController" nib but the view outlet was not set.

file‘s owner中的view属性没有设置，连线view属性和xib中的collectionView


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