二、通過純程式碼建立的UICollectionView的簡單使用
阿新 • • 發佈：2019-01-31
之前寫了一個Xib建立UiCollectionView的簡單使用的demo，現在寫個用純程式碼寫的，原理其實差不多，只是那個Cell之前是用XIb現在用一個繼承UiColelctionViewCell的類代替，如下所示：
1.首先建立一個CollectionCell的類繼承UIColelctionViewCell
@interface CollectionCell : UICollectionViewCell @property (nonatomic, strong) UIImageView *imageView; @property (nonatomic, strong) UILabel *label; @end
裡面的UIImageView和UILabel控制元件是我定義的加在cell上面的控制元件；
2.在OneViewController的.h檔案中實現三個協議：如下所示，並宣告UICollectionView控制元件
<span style="font-size:14px;">@interface OneViewController : UIViewController<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout> @property (nonatomic, strong)UICollectionView *collectionView; @property (nonatomic, strong)NSMutableArray *dataArray; @end</span>
3.在OneViewController的.m檔案中初始化UICollectionView控制元件
<span style="font-size:14px;"> UICollectionViewFlowLayout *flowLayout = [UICollectionViewFlowLayout new]; flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal; //水平滾動 self.collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, 100) collectionViewLayout:flowLayout]; self.collectionView.delegate = self; //實現代理 self.collectionView.dataSource = self; //實現資料來源方法 self.collectionView.showsHorizontalScrollIndicator = NO; [self.view addSubview:self.collectionView]; //註冊cell，通過建立的CollectionCell [self.collectionView registerClass:[CollectionCell class] forCellWithReuseIdentifier:@"CELL"];</span>
4.實現其相關的代理方法
<span style="font-size:14px;">#pragma mark UICollectionViewDelegateFlowLayout的代理方法
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{
return CGSizeMake(100, 100);
}
#pragma mark UICollectionViewDataSource的代理方法
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
return self.dataArray.count;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
CollectionCell *cell = (CollectionCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"CELL" forIndexPath:indexPath];
[cell.imageView setImage:[UIImage imageNamed:[self.dataArray objectAtIndex:indexPath.row]]];
[cell.label setText:[self.dataArray objectAtIndex:indexPath.row]];
cell.backgroundColor = [UIColor redColor];
return cell;
}
#pragma mark UICollectionViewDelegate的代理方法
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
CollectionCell *cell = (CollectionCell *)[collectionView cellForItemAtIndexPath:indexPath];
cell.backgroundColor = [UIColor greenColor];
}
-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath{
CollectionCell *cell = (CollectionCell *)[collectionView cellForItemAtIndexPath:indexPath];
cell.backgroundColor = [UIColor redColor];
}</span>
5.ok了執行完效果圖如下：
