UICollectionViewCells与UICollectionView中的数据以编程方式从数组中填充数据

Question

我有一个UICollectionView，我想用100个UICollectionViewCells填充它，每个UICollectionViewCells都有自己的唯一UILabel和从数组中获取的文本。我想以编程方式执行此操作（没有故事板）。

我试过它，因为下面发布，但由于某种原因只有第一个单元格正确渲染。

// Setting up the UICollectionView 
- (void)setupCollectionView { 
    UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init]; 
    CGRect newFrame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height * 0.5); 
    self.collectionView=[[UICollectionView alloc] initWithFrame:newFrame collectionViewLayout:layout]; 
    [self.collectionView setDataSource:self]; 
    [self.collectionView setDelegate:self]; 

    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cellIdentifier"]; 
    [self.collectionView setBackgroundColor:[UIColor clearColor]]; 
    [self.view addSubview:self.collectionView]; 
} 

//Trying to generate the unique cells with data 
- (UICollectionViewCell *) collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{ 

    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentifier" forIndexPath:indexPath]; 
    cell.backgroundColor = [UIColor yellowColor]; 

    UILabel *label = [[UILabel alloc] initWithFrame: cell.frame]; 
    label.text = [self.array objectAtIndex: indexPath.row]; 
    label.textColor = [UIColor blackColor]; 
    [cell.contentView addSubview:label]; 

    return cell; 
} 

注意：我的数组大小为100，随机生成数字。

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谢谢！

Answer 1

阵列的框架应该与它的细胞，而不是它的细胞的框架，谁是作为indexPath增长起源将增长的边界。另外，我们不希望无条件地创建标签，因为这些单元格会被重用。只有创建一个标签，如果一个不存在....

UILabel *label = (UILabel *)[cell viewWithTag:99]; 
if (!label) { 
    label = [[UILabel alloc] initWithFrame: cell.bounds]; // note use bounds here - which we want to be zero based since we're in the coordinate system of the cell 
    label.tag = 99; 
    label.text = [self.array objectAtIndex: indexPath.row]; 
    label.textColor = [UIColor blackColor]; 
    [cell.contentView addSubview:label]; 
} 
// unconditionally setup its text 
NSNumber *number = self.myArrayOfRandomNumbers[indexPath.row]; 
label.text = [number description];