1.当我们在开发过程中会屏幕均分成几个Item，在部分屏幕中会存在间隙问题，为了解决这个问题，直接上代码，新建FYUserCenterFlowLayout 继承 UICollectionViewFlowLayout工具类：
.h
NS_ASSUME_NONNULL_BEGIN
@interface FYUserCenterFlowLayout : UICollectionViewFlowLayout
@end
NS_ASSUME_NONNULL_END
.m
#import "FYUserCenterFlowLayout.h"
@implementation FYUserCenterFlowLayout
-(NSArray<__kindof UICollectionViewLayoutAttributes *> *)layoutAttributesForElementsInRect:(CGRect)rect
{
NSMutableArray *answer = [[super layoutAttributesForElementsInRect:rect] mutableCopy];
for(int i = 1; i < [answer count]; ++i) {
UICollectionViewLayoutAttributes *currentLayoutAttributes = answer[i];
UICollectionViewLayoutAttributes*prevLayoutAttributes=answer[i-1];
NSInteger maximumSpacing = 0;
NSInteger origin = CGRectGetMaxX(prevLayoutAttributes.frame);
if(origin + maximumSpacing + currentLayoutAttributes.frame.size.width < self. collectionViewContentSize.width) {
CGRect frame = currentLayoutAttributes.frame;
frame.origin.x = origin + maximumSpacing;
currentLayoutAttributes.frame = frame;
}
}
return answer;
}
@end
