objective-c - Setting minimumLineSpacing of UICollectionViewFlowLayout doesn't work, why?

Question

UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];

layout.minimumLineSpacing =10.0f;
 //2.初始化collectionView
_homeCollectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, Screen_width , Screen_height - 117) collectionViewLayout:layout];

The code is like this, I don’t know what caused the minimumLineSpacing attribute to fail

Answer 1

If the delegate object does not implement the
collectionView:layout:minimumLineSpacingForSectionAtIndex: method, the
flow layout uses the value in this property to set the spacing between
lines in a section.

For a vertically scrolling grid, this value represents the minimum
spacing between successive rows. For a horizontally scrolling grid,
this value represents the minimum spacing between successive columns.
This spacing is not applied to the space between the header and the
first line or between the last line and the footer.

The default value of this property is 10.0.

原因有很多，是否时实现了设置minimumLineSpacing的delegate，还和collectionView的滑动方向有关。