Question

我的UICollectionView有一个带有autolayout约束的UIImageView。我需要连续一定数量的单元格，因此如果单元格需要，则需要缩放图像。

即使我没有调整单元格的大小，但是在故事板中将UIimageView设置为大于预期尺寸的单元格，第一次填充单元格时图像大小不正确，但是当每个单元格在之后重复使用时，它们会完美缩放。

一旦细胞被重复使用，缩放就会起作用，但请问我错过了什么？

example view是第二次调用“球”中下方的reloaddata。第一个呼叫填充了前4个小区。第二个调用纠正了现在重用的单元格，但无法扩展4个新单元格内容。

以下是一些要求的代码。 generalBreakCollection成为焦点：

- (UICollectionViewCell *) collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {


if (collectionView == self.p1HiBreakCollection) {

    breakBallCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"P1Cell" forIndexPath:indexPath];

    UIImageView *collectionImageView = (UIImageView *)[cell viewWithTag:106];
    ballShot *selectedBall = [self.p1BreakBalls objectAtIndex:indexPath.row];
    cell.ball = [self.p1BreakBalls objectAtIndex:indexPath.row];
    collectionImageView.image = [UIImage imageNamed:selectedBall.imageNameLarge];


    return cell;
} else if (collectionView == self.p2HiBreakCollection) {

    breakBallCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"P2Cell" forIndexPath:indexPath];

    UIImageView *collectionImageView = (UIImageView *)[cell viewWithTag:108];
    ballShot *selectedBall = [self.p2BreakBalls objectAtIndex:indexPath.row];
    cell.ball = [self.p2BreakBalls objectAtIndex:indexPath.row];
    collectionImageView.image = [UIImage imageNamed:selectedBall.imageNameLarge];


    return cell;

} else {
    // generalBreakCollection


    breakBallCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"GeneralCell" forIndexPath:indexPath];

    ballShot *selectedBall = [self.breakShots objectAtIndex:indexPath.row];
    cell.ball = [self.breakShots objectAtIndex:indexPath.row];


    cell.ballStoreImage.image = [UIImage imageNamed:selectedBall.imageNameLarge];
    cell.ballStoreImage.highlightedImage = [UIImage imageNamed:[NSString stringWithFormat:@"highlighted_%@",selectedBall.imageNameLarge]];

    cell.ballStoreImage.contentMode = UIViewContentModeScaleAspectFit;
    return cell;
}
}

调整大小块包含：

- (CGSize)collectionView:(UICollectionView *)collectionView
              layout:(UICollectionViewLayout *)collectionViewLayout

sizeForItemAtIndexPath：（NSIndexPath *）indexPath {

if (collectionView == self.generalBreakCollection) {
    CGRect screenRect = [[UIScreen mainScreen] bounds];
    CGFloat screenWidth = screenRect.size.width;
    float cellWidth = screenWidth / 10.0; //Replace the divisor with the column count requirement. Make sure to have it in float.
    CGSize size = CGSizeMake(cellWidth, cellWidth);  
return size;  
}
else {
    CGSize defaultSize = [(UICollectionViewFlowLayout*)collectionViewLayout itemSize];
    return defaultSize    ;
}

}

我有自己的UICollectionViewCell类，带有UIImageView属性ballStoreImage。我没有用它做太多，但我把它链接到故事板中单元格内的UIImageView：

@property (strong, nonatomic) IBOutlet UIImageView *ballStoreImage;

Answer 1

在添加代码行之前，自动布局无法识别：

[[cell contentView] setFrame:[cell bounds]];

完整的块读取：

    } else {
    breakBallCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"breakCell" forIndexPath:indexPath];

    [[cell contentView] setFrame:[cell bounds]];


    ballShot *selectedBall = [self.breakShots objectAtIndex:indexPath.row];
    cell.ball = [self.breakShots objectAtIndex:indexPath.row];

    cell.ballStoreImage.image = [UIImage imageNamed:selectedBall.imageNameLarge];
    cell.ballStoreImage.highlightedImage = [UIImage imageNamed:[NSString stringWithFormat:@"highlighted_%@",selectedBall.imageNameLarge]];
    return cell;

}

内容未在第一个实例上的UICollectionViewCell内调整大小

1 个答案: